diff --git a/nixos/modules/config/getaddrinfo.nix b/nixos/modules/config/getaddrinfo.nix
index f18651a9e031..ddea509bfa78 100644
--- a/nixos/modules/config/getaddrinfo.nix
+++ b/nixos/modules/config/getaddrinfo.nix
@@ -18,7 +18,7 @@ let
     [
       "# Generated by NixOS module networking.getaddrinfo"
       "# Do not edit manually!"
-      "reload ${if cfg.reload then "yes" else "no"}"
+      "reload ${lib.boolToYesNo cfg.reload}"
     ]
     ++ formatTableEntries "label" cfg.label
     ++ formatTableEntries "precedence" cfg.precedence
diff --git a/nixos/modules/misc/locate.nix b/nixos/modules/misc/locate.nix
index 092852330437..0980e6f385a2 100644
--- a/nixos/modules/misc/locate.nix
+++ b/nixos/modules/misc/locate.nix
@@ -241,7 +241,7 @@ in
         PRUNEFS="${lib.concatStringsSep " " cfg.pruneFS}"
         PRUNENAMES="${lib.concatStringsSep " " cfg.pruneNames}"
         PRUNEPATHS="${lib.concatStringsSep " " cfg.prunePaths}"
-        PRUNE_BIND_MOUNTS="${if cfg.pruneBindMounts then "yes" else "no"}"
+        PRUNE_BIND_MOUNTS="${lib.boolToYesNo cfg.pruneBindMounts}"
       '';
 
       systemPackages = [ cfg.package ];
@@ -267,7 +267,7 @@ in
         ''
           exec ${cfg.package}/bin/updatedb \
             --output ${toString cfg.output} ${lib.concatStringsSep " " args} \
-            --prune-bind-mounts ${if cfg.pruneBindMounts then "yes" else "no"} \
+            --prune-bind-mounts ${lib.boolToYesNo cfg.pruneBindMounts} \
             ${lib.concatStringsSep " " cfg.extraFlags}
         '';
       serviceConfig = {
diff --git a/nixos/modules/programs/ssh.nix b/nixos/modules/programs/ssh.nix
index 443878715bc0..508d1961c770 100644
--- a/nixos/modules/programs/ssh.nix
+++ b/nixos/modules/programs/ssh.nix
@@ -357,7 +357,7 @@ in
       ]
       ++ lib.optional (!config.networking.enableIPv6) "AddressFamily inet"
       ++ lib.optional cfg.setXAuthLocation "XAuthLocation ${pkgs.xorg.xauth}/bin/xauth"
-      ++ lib.optional (cfg.forwardX11 != null) "ForwardX11 ${if cfg.forwardX11 then "yes" else "no"}"
+      ++ lib.optional (cfg.forwardX11 != null) "ForwardX11 ${lib.boolToYesNo cfg.forwardX11}"
       ++ lib.optional (
         cfg.pubkeyAcceptedKeyTypes != [ ]
       ) "PubkeyAcceptedKeyTypes ${builtins.concatStringsSep "," cfg.pubkeyAcceptedKeyTypes}"
diff --git a/nixos/modules/security/auditd.nix b/nixos/modules/security/auditd.nix
index bbe22fa6a5bc..f9e7fd6084c1 100644
--- a/nixos/modules/security/auditd.nix
+++ b/nixos/modules/security/auditd.nix
@@ -86,7 +86,7 @@ let
   prepareConfigValue =
     v:
     if lib.isBool v then
-      (if v then "yes" else "no")
+      lib.boolToYesNo v
     else if lib.isList v then
       lib.concatStringsSep " " (map prepareConfigValue v)
     else
diff --git a/nixos/modules/security/duosec.nix b/nixos/modules/security/duosec.nix
index b8ff3ae18856..3734bc89e402 100644
--- a/nixos/modules/security/duosec.nix
+++ b/nixos/modules/security/duosec.nix
@@ -6,8 +6,7 @@
 }:
 let
   cfg = config.security.duosec;
-
-  boolToStr = b: if b then "yes" else "no";
+  inherit (lib) boolToYesNo;
 
   configFilePam = ''
     [duo]
@@ -15,15 +14,15 @@ let
     host=${cfg.host}
     ${lib.optionalString (cfg.groups != "") ("groups=" + cfg.groups)}
     failmode=${cfg.failmode}
-    pushinfo=${boolToStr cfg.pushinfo}
-    autopush=${boolToStr cfg.autopush}
+    pushinfo=${boolToYesNo cfg.pushinfo}
+    autopush=${boolToYesNo cfg.autopush}
     prompts=${toString cfg.prompts}
-    fallback_local_ip=${boolToStr cfg.fallbackLocalIP}
+    fallback_local_ip=${boolToYesNo cfg.fallbackLocalIP}
   '';
 
   configFileLogin = configFilePam + ''
-    motd=${boolToStr cfg.motd}
-    accept_env_factor=${boolToStr cfg.acceptEnvFactor}
+    motd=${boolToYesNo cfg.motd}
+    accept_env_factor=${boolToYesNo cfg.acceptEnvFactor}
   '';
 in
 {
diff --git a/nixos/modules/security/pam_mount.nix b/nixos/modules/security/pam_mount.nix
index 62deec4ca487..d6459c2598f9 100644
--- a/nixos/modules/security/pam_mount.nix
+++ b/nixos/modules/security/pam_mount.nix
@@ -170,9 +170,7 @@ in
           <pam_mount>
           <debug enable="${toString cfg.debugLevel}" />
           <!-- if activated, requires ofl from hxtools to be present -->
-          <logout wait="${toString cfg.logoutWait}" hup="${if cfg.logoutHup then "yes" else "no"}" term="${
-            if cfg.logoutTerm then "yes" else "no"
-          }" kill="${if cfg.logoutKill then "yes" else "no"}" />
+          <logout wait="${toString cfg.logoutWait}" hup="${lib.boolToYesNo cfg.logoutHup}" term="${lib.boolToYesNo cfg.logoutTerm}" kill="${lib.boolToYesNo cfg.logoutKill}" />
           <!-- set PATH variable for pam_mount module -->
           <path>${lib.makeBinPath ([ pkgs.util-linux ] ++ cfg.additionalSearchPaths)}</path>
           <!-- create mount point if not present -->
diff --git a/nixos/modules/security/tpm2.nix b/nixos/modules/security/tpm2.nix
index 29eece1ef794..bc05c75669a3 100644
--- a/nixos/modules/security/tpm2.nix
+++ b/nixos/modules/security/tpm2.nix
@@ -39,7 +39,7 @@ let
           ima_log_file = cfg.fapi.imaLogFile;
         }
         // lib.optionalAttrs (cfg.fapi.ekCertLess != null) {
-          ek_cert_less = if cfg.fapi.ekCertLess then "yes" else "no";
+          ek_cert_less = lib.boolToYesNo cfg.fapi.ekCertLess;
         }
         // lib.optionalAttrs (cfg.fapi.ekFingerprint != null) { ek_fingerprint = cfg.fapi.ekFingerprint; }
       )
diff --git a/nixos/modules/services/backup/bacula.nix b/nixos/modules/services/backup/bacula.nix
index cc2e603bf3f9..45d8557e609d 100644
--- a/nixos/modules/services/backup/bacula.nix
+++ b/nixos/modules/services/backup/bacula.nix
@@ -10,6 +10,7 @@
 
 let
   inherit (lib)
+    boolToYesNo
     concatStringsSep
     literalExpression
     mapAttrsToList
@@ -21,16 +22,15 @@ let
     ;
   libDir = "/var/lib/bacula";
 
-  yes_no = bool: if bool then "yes" else "no";
   tls_conf =
     tls_cfg:
     optionalString tls_cfg.enable (
       concatStringsSep "\n" (
         [ "TLS Enable = yes;" ]
-        ++ optional (tls_cfg.require != null) "TLS Require = ${yes_no tls_cfg.require};"
+        ++ optional (tls_cfg.require != null) "TLS Require = ${boolToYesNo tls_cfg.require};"
         ++ optional (tls_cfg.certificate != null) ''TLS Certificate = "${tls_cfg.certificate}";''
         ++ [ ''TLS Key = "${tls_cfg.key}";'' ]
-        ++ optional (tls_cfg.verifyPeer != null) "TLS Verify Peer = ${yes_no tls_cfg.verifyPeer};"
+        ++ optional (tls_cfg.verifyPeer != null) "TLS Verify Peer = ${boolToYesNo tls_cfg.verifyPeer};"
         ++ optional (
           tls_cfg.allowedCN != [ ]
         ) "TLS Allowed CN = ${concatStringsSep " " (tls_cfg.allowedCN)};"
diff --git a/nixos/modules/services/databases/cassandra.nix b/nixos/modules/services/databases/cassandra.nix
index 27b7a5b94db2..2161fc13ea59 100644
--- a/nixos/modules/services/databases/cassandra.nix
+++ b/nixos/modules/services/databases/cassandra.nix
@@ -504,7 +504,7 @@ in
         MAX_HEAP_SIZE = toString cfg.maxHeapSize;
         HEAP_NEWSIZE = toString cfg.heapNewSize;
         MALLOC_ARENA_MAX = toString cfg.mallocArenaMax;
-        LOCAL_JMX = if cfg.remoteJmx then "no" else "yes";
+        LOCAL_JMX = lib.boolToYesNo (!cfg.remoteJmx);
         JMX_PORT = toString cfg.jmxPort;
       };
       wantedBy = [ "multi-user.target" ];
diff --git a/nixos/modules/services/mail/cyrus-imap.nix b/nixos/modules/services/mail/cyrus-imap.nix
index 3ffd74451b6c..9ee7cf8ee44b 100644
--- a/nixos/modules/services/mail/cyrus-imap.nix
+++ b/nixos/modules/services/mail/cyrus-imap.nix
@@ -15,6 +15,7 @@ let
     optionalString
     generators
     mapAttrsToList
+    boolToYesNo
     ;
   inherit (lib.strings) concatStringsSep;
   inherit (lib.types)
@@ -63,7 +64,7 @@ let
         mkValueString =
           v:
           if builtins.isBool v then
-            if v then "yes" else "no"
+            boolToYesNo v
           else if builtins.isList v then
             concatStringsSep " " v
           else
diff --git a/nixos/modules/services/mail/rspamd.nix b/nixos/modules/services/mail/rspamd.nix
index 5b09cfb217fb..715376e24f88 100644
--- a/nixos/modules/services/mail/rspamd.nix
+++ b/nixos/modules/services/mail/rspamd.nix
@@ -211,9 +211,7 @@ let
         ''
           worker "${value.type}" {
             type = "${value.type}";
-            ${optionalString (value.enable != null)
-              "enabled = ${if value.enable != false then "yes" else "no"};"
-            }
+            ${optionalString (value.enable != null) "enabled = ${lib.boolToYesNo (value.enable != false)};"}
             ${mkBindSockets value.enable value.bindSockets}
             ${optionalString (value.count != null) "count = ${toString value.count};"}
             ${concatStringsSep "\n  " (map (each: ".include \"${each}\"") value.includes)}
diff --git a/nixos/modules/services/misc/gammu-smsd.nix b/nixos/modules/services/misc/gammu-smsd.nix
index 85f3d2fa94a9..518a9c4f0065 100644
--- a/nixos/modules/services/misc/gammu-smsd.nix
+++ b/nixos/modules/services/misc/gammu-smsd.nix
@@ -11,7 +11,7 @@ let
     [gammu]
     Device = ${cfg.device.path}
     Connection = ${cfg.device.connection}
-    SynchronizeTime = ${if cfg.device.synchronizeTime then "yes" else "no"}
+    SynchronizeTime = ${lib.boolToYesNo cfg.device.synchronizeTime}
     LogFormat = ${cfg.log.format}
     ${lib.optionalString (cfg.device.pin != null) "PIN = ${cfg.device.pin}"}
     ${cfg.extraConfig.gammu}
diff --git a/nixos/modules/services/misc/mediatomb.nix b/nixos/modules/services/misc/mediatomb.nix
index eac446817ae7..1b92947db696 100644
--- a/nixos/modules/services/misc/mediatomb.nix
+++ b/nixos/modules/services/misc/mediatomb.nix
@@ -12,7 +12,6 @@ let
   opt = options.services.mediatomb;
   name = cfg.package.pname;
   pkg = cfg.package;
-  optionYesNo = option: if option then "yes" else "no";
   # configuration on media directory
   mediaDirectory = {
     options = {
@@ -36,7 +35,7 @@ let
   };
   toMediaDirectory =
     d:
-    "<directory location=\"${d.path}\" mode=\"inotify\" recursive=\"${optionYesNo d.recursive}\" hidden-files=\"${optionYesNo d.hidden-files}\" />\n";
+    "<directory location=\"${d.path}\" mode=\"inotify\" recursive=\"${lib.boolToYesNo d.recursive}\" hidden-files=\"${lib.boolToYesNo d.hidden-files}\" />\n";
 
   transcodingConfig =
     if cfg.transcoding then
@@ -89,13 +88,13 @@ let
           <home>${cfg.dataDir}</home>
           <interface>${cfg.interface}</interface>
           <webroot>${pkg}/share/${name}/web</webroot>
-          <pc-directory upnp-hide="${optionYesNo cfg.pcDirectoryHide}"/>
+          <pc-directory upnp-hide="${lib.boolToYesNo cfg.pcDirectoryHide}"/>
           <storage>
             <sqlite3 enabled="yes">
               <database-file>${name}.db</database-file>
             </sqlite3>
           </storage>
-          <protocolInfo extend="${optionYesNo cfg.ps3Support}"/>
+          <protocolInfo extend="${lib.boolToYesNo cfg.ps3Support}"/>
           ${lib.optionalString cfg.dsmSupport ''
             <custom-http-headers>
               <add header="X-User-Agent: redsonic"/>
diff --git a/nixos/modules/services/network-filesystems/orangefs/server.nix b/nixos/modules/services/network-filesystems/orangefs/server.nix
index 99d7b27011c2..d3047af4aa91 100644
--- a/nixos/modules/services/network-filesystems/orangefs/server.nix
+++ b/nixos/modules/services/network-filesystems/orangefs/server.nix
@@ -50,8 +50,8 @@ let
       </DataHandleRanges>
 
       <StorageHints>
-      TroveSyncMeta ${if fs.troveSyncMeta then "yes" else "no"}
-      TroveSyncData ${if fs.troveSyncData then "yes" else "no"}
+      TroveSyncMeta ${lib.boolToYesNo fs.troveSyncMeta}
+      TroveSyncData ${lib.boolToYesNo fs.troveSyncData}
       ${fs.extraStorageHints}
       </StorageHints>
 
diff --git a/nixos/modules/services/networking/avahi-daemon.nix b/nixos/modules/services/networking/avahi-daemon.nix
index b1ed28980cfe..28efc39f8bce 100644
--- a/nixos/modules/services/networking/avahi-daemon.nix
+++ b/nixos/modules/services/networking/avahi-daemon.nix
@@ -7,8 +7,6 @@
 let
   cfg = config.services.avahi;
 
-  yesNo = yes: if yes then "yes" else "no";
-
   avahiDaemonConf =
     with cfg;
     pkgs.writeText "avahi-daemon.conf" ''
@@ -21,8 +19,8 @@ let
         lib.optionalString (hostName != "") "host-name=${hostName}"
       }
       browse-domains=${lib.concatStringsSep ", " browseDomains}
-      use-ipv4=${yesNo ipv4}
-      use-ipv6=${yesNo ipv6}
+      use-ipv4=${lib.boolToYesNo ipv4}
+      use-ipv6=${lib.boolToYesNo ipv6}
       ${lib.optionalString (
         allowInterfaces != null
       ) "allow-interfaces=${lib.concatStringsSep "," allowInterfaces}"}
@@ -30,22 +28,22 @@ let
         denyInterfaces != null
       ) "deny-interfaces=${lib.concatStringsSep "," denyInterfaces}"}
       ${lib.optionalString (domainName != null) "domain-name=${domainName}"}
-      allow-point-to-point=${yesNo allowPointToPoint}
+      allow-point-to-point=${lib.boolToYesNo allowPointToPoint}
       ${lib.optionalString (cacheEntriesMax != null) "cache-entries-max=${toString cacheEntriesMax}"}
 
       [wide-area]
-      enable-wide-area=${yesNo wideArea}
+      enable-wide-area=${lib.boolToYesNo wideArea}
 
       [publish]
-      disable-publishing=${yesNo (!publish.enable)}
-      disable-user-service-publishing=${yesNo (!publish.userServices)}
-      publish-addresses=${yesNo (publish.userServices || publish.addresses)}
-      publish-hinfo=${yesNo publish.hinfo}
-      publish-workstation=${yesNo publish.workstation}
-      publish-domain=${yesNo publish.domain}
+      disable-publishing=${lib.boolToYesNo (!publish.enable)}
+      disable-user-service-publishing=${lib.boolToYesNo (!publish.userServices)}
+      publish-addresses=${lib.boolToYesNo (publish.userServices || publish.addresses)}
+      publish-hinfo=${lib.boolToYesNo publish.hinfo}
+      publish-workstation=${lib.boolToYesNo publish.workstation}
+      publish-domain=${lib.boolToYesNo publish.domain}
 
       [reflector]
-      enable-reflector=${yesNo reflector}
+      enable-reflector=${lib.boolToYesNo reflector}
       ${extraConfig}
     '';
 in
diff --git a/nixos/modules/services/networking/ddclient.nix b/nixos/modules/services/networking/ddclient.nix
index 54e488db9856..773387939a7c 100644
--- a/nixos/modules/services/networking/ddclient.nix
+++ b/nixos/modules/services/networking/ddclient.nix
@@ -6,7 +6,6 @@
 }:
 let
   cfg = config.services.ddclient;
-  boolToStr = bool: if bool then "yes" else "no";
   dataDir = "/var/lib/ddclient";
   StateDirectory = builtins.baseNameOf dataDir;
   RuntimeDirectory = StateDirectory;
@@ -33,10 +32,10 @@ let
     ${lib.optionalString (cfg.script != "") "script=${cfg.script}"}
     ${lib.optionalString (cfg.server != "") "server=${cfg.server}"}
     ${lib.optionalString (cfg.zone != "") "zone=${cfg.zone}"}
-    ssl=${boolToStr cfg.ssl}
+    ssl=${lib.boolToYesNo cfg.ssl}
     wildcard=YES
-    quiet=${boolToStr cfg.quiet}
-    verbose=${boolToStr cfg.verbose}
+    quiet=${lib.boolToYesNo cfg.quiet}
+    verbose=${lib.boolToYesNo cfg.verbose}
     ${cfg.extraConfig}
     ${lib.concatStringsSep "," cfg.domains}
   '';
diff --git a/nixos/modules/services/networking/frr.nix b/nixos/modules/services/networking/frr.nix
index fac18c6a246c..73c194ac060c 100644
--- a/nixos/modules/services/networking/frr.nix
+++ b/nixos/modules/services/networking/frr.nix
@@ -82,7 +82,7 @@ let
 
   isEnabled = service: cfg.${service}.enable;
 
-  daemonLine = d: "${d}=${if isEnabled d then "yes" else "no"}";
+  daemonLine = d: "${d}=${lib.boolToYesNo (isEnabled d)}";
 
   configFile =
     if cfg.configFile != null then
diff --git a/nixos/modules/services/networking/miniupnpd.nix b/nixos/modules/services/networking/miniupnpd.nix
index ccbddbf3d5a1..c723ff16d3cd 100644
--- a/nixos/modules/services/networking/miniupnpd.nix
+++ b/nixos/modules/services/networking/miniupnpd.nix
@@ -11,8 +11,8 @@ let
   cfg = config.services.miniupnpd;
   configFile = pkgs.writeText "miniupnpd.conf" ''
     ext_ifname=${cfg.externalInterface}
-    enable_natpmp=${if cfg.natpmp then "yes" else "no"}
-    enable_upnp=${if cfg.upnp then "yes" else "no"}
+    enable_natpmp=${boolToYesNo cfg.natpmp}
+    enable_upnp=${boolToYesNo cfg.upnp}
 
     ${concatMapStrings (range: ''
       listening_ip=${range}
diff --git a/nixos/modules/services/networking/nsd.nix b/nixos/modules/services/networking/nsd.nix
index bc6aa5ae3fff..46d9d084d7d7 100644
--- a/nixos/modules/services/networking/nsd.nix
+++ b/nixos/modules/services/networking/nsd.nix
@@ -100,19 +100,19 @@ let
       # interfaces
     ${forEach "  ip-address: " cfg.interfaces}
 
-      ip-freebind:         ${yesOrNo cfg.ipFreebind}
-      hide-version:        ${yesOrNo cfg.hideVersion}
+      ip-freebind:         ${boolToYesNo cfg.ipFreebind}
+      hide-version:        ${boolToYesNo cfg.hideVersion}
       identity:            "${cfg.identity}"
-      ip-transparent:      ${yesOrNo cfg.ipTransparent}
-      do-ip4:              ${yesOrNo cfg.ipv4}
+      ip-transparent:      ${boolToYesNo cfg.ipTransparent}
+      do-ip4:              ${boolToYesNo cfg.ipv4}
       ipv4-edns-size:      ${toString cfg.ipv4EDNSSize}
-      do-ip6:              ${yesOrNo cfg.ipv6}
+      do-ip6:              ${boolToYesNo cfg.ipv6}
       ipv6-edns-size:      ${toString cfg.ipv6EDNSSize}
-      log-time-ascii:      ${yesOrNo cfg.logTimeAscii}
+      log-time-ascii:      ${boolToYesNo cfg.logTimeAscii}
       ${maybeString "nsid: " cfg.nsid}
       port:                ${toString cfg.port}
-      reuseport:           ${yesOrNo cfg.reuseport}
-      round-robin:         ${yesOrNo cfg.roundRobin}
+      reuseport:           ${boolToYesNo cfg.reuseport}
+      round-robin:         ${boolToYesNo cfg.roundRobin}
       server-count:        ${toString cfg.serverCount}
       ${maybeToString "statistics: " cfg.statistics}
       tcp-count:           ${toString cfg.tcpCount}
@@ -121,7 +121,7 @@ let
       verbosity:           ${toString cfg.verbosity}
       ${maybeString "version: " cfg.version}
       xfrd-reload-timeout: ${toString cfg.xfrdReloadTimeout}
-      zonefiles-check:     ${yesOrNo cfg.zonefilesCheck}
+      zonefiles-check:     ${boolToYesNo cfg.zonefilesCheck}
       zonefiles-write:     ${toString cfg.zonefilesWrite}
 
       ${maybeString "rrl-ipv4-prefix-length: " cfg.ratelimit.ipv4PrefixLength}
@@ -134,7 +134,7 @@ let
     ${keyConfigFile}
 
     remote-control:
-      control-enable:    ${yesOrNo cfg.remoteControl.enable}
+      control-enable:    ${boolToYesNo cfg.remoteControl.enable}
       control-key-file:  "${cfg.remoteControl.controlKeyFile}"
       control-cert-file: "${cfg.remoteControl.controlCertFile}"
     ${forEach "  control-interface: " cfg.remoteControl.interfaces}
@@ -147,7 +147,6 @@ let
     ${cfg.extraConfig}
   '';
 
-  yesOrNo = b: if b then "yes" else "no";
   maybeString = prefix: x: optionalString (x != null) ''${prefix} "${x}"'';
   maybeToString = prefix: x: optionalString (x != null) ''${prefix} ${toString x}'';
   forEach = pre: l: concatMapStrings (x: pre + x + "\n") l;
@@ -183,8 +182,8 @@ let
       ${maybeToString "max-retry-time:   " zone.maxRetrySecs}
       ${maybeToString "min-retry-time:   " zone.minRetrySecs}
 
-      allow-axfr-fallback: ${yesOrNo zone.allowAXFRFallback}
-      multi-master-check: ${yesOrNo zone.multiMasterCheck}
+      allow-axfr-fallback: ${boolToYesNo zone.allowAXFRFallback}
+      multi-master-check: ${boolToYesNo zone.multiMasterCheck}
     ${forEach "  allow-notify: " zone.allowNotify}
     ${forEach "  request-xfr: " zone.requestXFR}
 
diff --git a/nixos/modules/services/networking/pdns-recursor.nix b/nixos/modules/services/networking/pdns-recursor.nix
index 3185dd1b9696..172f45c61331 100644
--- a/nixos/modules/services/networking/pdns-recursor.nix
+++ b/nixos/modules/services/networking/pdns-recursor.nix
@@ -21,7 +21,6 @@ let
     ];
   configType = with types; attrsOf (nullOr (oneOrMore valueType));
 
-  toBool = val: if val then "yes" else "no";
   serialize =
     val:
     with types;
@@ -32,7 +31,7 @@ let
     else if path.check val then
       toString val
     else if bool.check val then
-      toBool val
+      boolToYesNo val
     else if builtins.isList val then
       (concatMapStringsSep "," serialize val)
     else
diff --git a/nixos/modules/services/networking/smartdns.nix b/nixos/modules/services/networking/smartdns.nix
index d60c5cf19b84..761f3c3e6a14 100644
--- a/nixos/modules/services/networking/smartdns.nix
+++ b/nixos/modules/services/networking/smartdns.nix
@@ -23,7 +23,7 @@ let
     with generators;
     toKeyValue {
       mkKeyValue = mkKeyValueDefault {
-        mkValueString = v: if isBool v then if v then "yes" else "no" else mkValueStringDefault { } v;
+        mkValueString = v: if isBool v then boolToYesNo v else mkValueStringDefault { } v;
       } " ";
       listsAsDuplicateKeys = true; # Allowing duplications because we need to deal with multiple entries with the same key.
     } cfg.settings
diff --git a/nixos/modules/services/networking/ssh/sshd.nix b/nixos/modules/services/networking/ssh/sshd.nix
index c56193cb4f83..ac7d43f81e77 100644
--- a/nixos/modules/services/networking/ssh/sshd.nix
+++ b/nixos/modules/services/networking/ssh/sshd.nix
@@ -484,7 +484,6 @@ in
               };
               UseDns = lib.mkOption {
                 type = lib.types.nullOr lib.types.bool;
-                # apply if cfg.useDns then "yes" else "no"
                 default = false;
                 description = ''
                   Specifies whether {manpage}`sshd(8)` should look up the remote host name, and to check that the resolved host name for
diff --git a/nixos/modules/services/networking/strongswan-swanctl/param-constructors.nix b/nixos/modules/services/networking/strongswan-swanctl/param-constructors.nix
index cb4ef1079016..82b38d18c639 100644
--- a/nixos/modules/services/networking/strongswan-swanctl/param-constructors.nix
+++ b/nixos/modules/services/networking/strongswan-swanctl/param-constructors.nix
@@ -97,7 +97,7 @@ rec {
       default = null;
       description = documentDefault description strongswanDefault;
     };
-    render = single (b: if b then "yes" else "no");
+    render = single boolToYesNo;
   };
   yes = true;
   no = false;
diff --git a/nixos/modules/services/networking/stunnel.nix b/nixos/modules/services/networking/stunnel.nix
index 9ff040191361..9ce2451b4231 100644
--- a/nixos/modules/services/networking/stunnel.nix
+++ b/nixos/modules/services/networking/stunnel.nix
@@ -7,7 +7,6 @@
 let
 
   cfg = config.services.stunnel;
-  yesNo = val: if val then "yes" else "no";
 
   verifyRequiredField = type: field: n: c: {
     assertion = lib.hasAttr field c;
@@ -23,13 +22,7 @@ let
 
   removeNulls = lib.mapAttrs (_: lib.filterAttrs (_: v: v != null));
   mkValueString =
-    v:
-    if v == true then
-      "yes"
-    else if v == false then
-      "no"
-    else
-      lib.generators.mkValueStringDefault { } v;
+    v: if lib.isBool v then lib.boolToYesNo v else lib.generators.mkValueStringDefault { } v;
   generateConfig =
     c:
     lib.generators.toINI {
diff --git a/nixos/modules/services/networking/tayga.nix b/nixos/modules/services/networking/tayga.nix
index 7ed0cf51e561..f7221bdaf8c7 100644
--- a/nixos/modules/services/networking/tayga.nix
+++ b/nixos/modules/services/networking/tayga.nix
@@ -28,7 +28,7 @@ let
       log ${concatStringsSep " " cfg.log}
     ''}
 
-    wkpf-strict ${if cfg.wkpfStrict then "yes" else "no"}
+    wkpf-strict ${boolToYesNo cfg.wkpfStrict}
   '';
 
   addrOpts =
diff --git a/nixos/modules/services/networking/unbound.nix b/nixos/modules/services/networking/unbound.nix
index 7ad0c53c17e9..219ca9fc13a9 100644
--- a/nixos/modules/services/networking/unbound.nix
+++ b/nixos/modules/services/networking/unbound.nix
@@ -9,8 +9,6 @@ with lib;
 let
   cfg = config.services.unbound;
 
-  yesOrNo = v: if v then "yes" else "no";
-
   toOption =
     indent: n: v:
     "${indent}${toString n}: ${v}";
@@ -22,7 +20,7 @@ let
     else if isInt v then
       (toOption indent n (toString v))
     else if isBool v then
-      (toOption indent n (yesOrNo v))
+      (toOption indent n (lib.boolToYesNo v))
     else if isString v then
       (toOption indent n v)
     else if isList v then
diff --git a/nixos/modules/services/networking/xinetd.nix b/nixos/modules/services/networking/xinetd.nix
index 71a258fbfee1..d33b4d97519b 100644
--- a/nixos/modules/services/networking/xinetd.nix
+++ b/nixos/modules/services/networking/xinetd.nix
@@ -31,7 +31,7 @@ let
       ${optionalString (srv.flags != "") "flags = ${srv.flags}"}
       socket_type = ${if srv.protocol == "udp" then "dgram" else "stream"}
       ${optionalString (srv.port != 0) "port        = ${toString srv.port}"}
-      wait        = ${if srv.protocol == "udp" then "yes" else "no"}
+      wait        = ${lib.boolToYesNo (srv.protocol == "udp")}
       user        = ${srv.user}
       server      = ${srv.server}
       ${optionalString (srv.serverArgs != "") "server_args = ${srv.serverArgs}"}
diff --git a/nixos/modules/tasks/network-interfaces-systemd.nix b/nixos/modules/tasks/network-interfaces-systemd.nix
index 653fafb9b216..14f9108c160d 100644
--- a/nixos/modules/tasks/network-interfaces-systemd.nix
+++ b/nixos/modules/tasks/network-interfaces-systemd.nix
@@ -18,7 +18,7 @@ let
 
   interfaceRoutes = i: i.ipv4.routes ++ optionals cfg.enableIPv6 i.ipv6.routes;
 
-  dhcpStr = useDHCP: if useDHCP == true || useDHCP == null then "yes" else "no";
+  dhcpStr = useDHCP: boolToYesNo (useDHCP == true || useDHCP == null);
 
   slaves =
     concatLists (map (bond: bond.interfaces) (attrValues cfg.bonds))
diff --git a/pkgs/applications/misc/redshift/default.nix b/pkgs/applications/misc/redshift/default.nix
index 6ac94dc2906b..aec14488480b 100644
--- a/pkgs/applications/misc/redshift/default.nix
+++ b/pkgs/applications/misc/redshift/default.nix
@@ -70,12 +70,12 @@ let
       ++ lib.optionals (pname == "gammastep") [ wayland-scanner ];
 
       configureFlags = [
-        "--enable-randr=${if withRandr then "yes" else "no"}"
-        "--enable-geoclue2=${if withGeoclue then "yes" else "no"}"
-        "--enable-drm=${if withDrm then "yes" else "no"}"
-        "--enable-vidmode=${if withVidmode then "yes" else "no"}"
-        "--enable-quartz=${if withQuartz then "yes" else "no"}"
-        "--enable-corelocation=${if withCoreLocation then "yes" else "no"}"
+        "--enable-randr=${lib.boolToYesNo withRandr}"
+        "--enable-geoclue2=${lib.boolToYesNo withGeoclue}"
+        "--enable-drm=${lib.boolToYesNo withDrm}"
+        "--enable-vidmode=${lib.boolToYesNo withVidmode}"
+        "--enable-quartz=${lib.boolToYesNo withQuartz}"
+        "--enable-corelocation=${lib.boolToYesNo withCoreLocation}"
       ]
       ++ lib.optionals (pname == "gammastep") [
         "--with-systemduserunitdir=${placeholder "out"}/lib/systemd/user/"
diff --git a/pkgs/build-support/release/debian-build.nix b/pkgs/build-support/release/debian-build.nix
index 27afc3a117fa..2359587665b8 100644
--- a/pkgs/build-support/release/debian-build.nix
+++ b/pkgs/build-support/release/debian-build.nix
@@ -69,7 +69,7 @@ vmTools.runInLinuxImage (
           # the log file
           export PAGER=cat
           ${checkinstall}/sbin/checkinstall --nodoc -y -D \
-            --fstrans=${if fsTranslation then "yes" else "no"} \
+            --fstrans=${lib.boolToYesNo fsTranslation} \
             --requires="${lib.concatStringsSep "," debRequires}" \
             --provides="${lib.concatStringsSep "," debProvides}" \
             ${
diff --git a/pkgs/by-name/ap/apr/package.nix b/pkgs/by-name/ap/apr/package.nix
index 8ded7258aca7..f9feea54a782 100644
--- a/pkgs/by-name/ap/apr/package.nix
+++ b/pkgs/by-name/ap/apr/package.nix
@@ -40,7 +40,7 @@ stdenv.mkDerivation rec {
       # These answers are valid on x86_64-linux and aarch64-linux.
       # TODO: provide all valid answers for BSD.
       "ac_cv_file__dev_zero=yes"
-      "ac_cv_func_setpgrp_void=${if stdenv.hostPlatform.isBSD then "no" else "yes"}"
+      "ac_cv_func_setpgrp_void=${lib.boolToYesNo (!stdenv.hostPlatform.isBSD)}"
       "apr_cv_tcp_nodelay_with_cork=yes"
       "ac_cv_define_PTHREAD_PROCESS_SHARED=yes"
       "apr_cv_process_shared_works=yes"
diff --git a/pkgs/by-name/ba/bacula/package.nix b/pkgs/by-name/ba/bacula/package.nix
index 74007248fd63..9397eab8c4dd 100644
--- a/pkgs/by-name/ba/bacula/package.nix
+++ b/pkgs/by-name/ba/bacula/package.nix
@@ -50,7 +50,7 @@ stdenv.mkDerivation rec {
   ]
   ++
     lib.optional (stdenv.buildPlatform != stdenv.hostPlatform)
-      "ac_cv_func_setpgrp_void=${if stdenv.hostPlatform.isBSD then "no" else "yes"}"
+      "ac_cv_func_setpgrp_void=${lib.boolToYesNo (!stdenv.hostPlatform.isBSD)}"
   ++ lib.optionals stdenv.hostPlatform.isDarwin [
     # bacula’s `configure` script fails to detect CoreFoundation correctly,
     # but these symbols are available in the nixpkgs CoreFoundation framework.
diff --git a/pkgs/by-name/co/colpack/package.nix b/pkgs/by-name/co/colpack/package.nix
index 897b137cd2c9..56bb94293a0e 100644
--- a/pkgs/by-name/co/colpack/package.nix
+++ b/pkgs/by-name/co/colpack/package.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
   nativeBuildInputs = [ autoreconfHook ];
 
   configureFlags = [
-    "--enable-openmp=${if stdenv.hostPlatform.isLinux then "yes" else "no"}"
+    "--enable-openmp=${lib.boolToYesNo stdenv.hostPlatform.isLinux}"
     "--enable-examples=no"
   ];
 
diff --git a/pkgs/by-name/do/dovecot/package.nix b/pkgs/by-name/do/dovecot/package.nix
index 1dce4874455d..5dd75ba1b615 100644
--- a/pkgs/by-name/do/dovecot/package.nix
+++ b/pkgs/by-name/do/dovecot/package.nix
@@ -155,9 +155,9 @@ stdenv.mkDerivation rec {
     "--with-textcat"
   ]
   ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
-    "i_cv_epoll_works=${if stdenv.hostPlatform.isLinux then "yes" else "no"}"
-    "i_cv_posix_fallocate_works=${if stdenv.hostPlatform.isDarwin then "no" else "yes"}"
-    "i_cv_inotify_works=${if stdenv.hostPlatform.isLinux then "yes" else "no"}"
+    "i_cv_epoll_works=${lib.boolToYesNo stdenv.hostPlatform.isLinux}"
+    "i_cv_posix_fallocate_works=${lib.boolToYesNo stdenv.hostPlatform.isDarwin}"
+    "i_cv_inotify_works=${lib.boolToYesNo stdenv.hostPlatform.isLinux}"
     "i_cv_signed_size_t=no"
     "i_cv_signed_time_t=yes"
     "i_cv_c99_vsnprintf=yes"
diff --git a/pkgs/by-name/i2/i2pd/package.nix b/pkgs/by-name/i2/i2pd/package.nix
index 598ffdc52936..83b9fa9aa0cb 100644
--- a/pkgs/by-name/i2/i2pd/package.nix
+++ b/pkgs/by-name/i2/i2pd/package.nix
@@ -38,7 +38,7 @@ stdenv.mkDerivation rec {
   ];
 
   makeFlags = [
-    "USE_UPNP=${if upnpSupport then "yes" else "no"}"
+    "USE_UPNP=${lib.boolToYesNo upnpSupport}"
   ];
 
   enableParallelBuilding = true;
diff --git a/pkgs/by-name/li/libcap/package.nix b/pkgs/by-name/li/libcap/package.nix
index 7abcdb8d24b8..76e0ee1d0fe6 100644
--- a/pkgs/by-name/li/libcap/package.nix
+++ b/pkgs/by-name/li/libcap/package.nix
@@ -56,7 +56,7 @@ stdenv.mkDerivation rec {
 
   makeFlags = [
     "lib=lib"
-    "PAM_CAP=${if usePam then "yes" else "no"}"
+    "PAM_CAP=${lib.boolToYesNo usePam}"
     "BUILD_CC=$(CC_FOR_BUILD)"
     "CC:=$(CC)"
     "CROSS_COMPILE=${stdenv.cc.targetPrefix}"
diff --git a/pkgs/by-name/li/libdaemon/package.nix b/pkgs/by-name/li/libdaemon/package.nix
index 7be36bcece73..5a2013bfe03c 100644
--- a/pkgs/by-name/li/libdaemon/package.nix
+++ b/pkgs/by-name/li/libdaemon/package.nix
@@ -26,7 +26,7 @@ stdenv.mkDerivation rec {
   ]
   ++ lib.optionals (stdenv.hostPlatform != stdenv.buildPlatform) [
     # Can't run this test while cross-compiling
-    "ac_cv_func_setpgrp_void=${if stdenv.hostPlatform.isBSD then "no" else "yes"}"
+    "ac_cv_func_setpgrp_void=${lib.boolToYesNo (!stdenv.hostPlatform.isBSD)}"
   ];
 
   meta = {
diff --git a/pkgs/by-name/li/libepoxy/package.nix b/pkgs/by-name/li/libepoxy/package.nix
index c408b12bac40..c73090a25a29 100644
--- a/pkgs/by-name/li/libepoxy/package.nix
+++ b/pkgs/by-name/li/libepoxy/package.nix
@@ -63,8 +63,8 @@ stdenv.mkDerivation (finalAttrs: {
     ];
 
   mesonFlags = [
-    "-Degl=${if (x11Support && !stdenv.hostPlatform.isDarwin) then "yes" else "no"}"
-    "-Dglx=${if x11Support then "yes" else "no"}"
+    "-Degl=${lib.boolToYesNo (x11Support && !stdenv.hostPlatform.isDarwin)}"
+    "-Dglx=${lib.boolToYesNo x11Support}"
     "-Dtests=${lib.boolToString finalAttrs.finalPackage.doCheck}"
     "-Dx11=${lib.boolToString x11Support}"
   ];
diff --git a/pkgs/by-name/li/libgpiod/package.nix b/pkgs/by-name/li/libgpiod/package.nix
index b40cb39b86ff..ed6b3ca2fa1c 100644
--- a/pkgs/by-name/li/libgpiod/package.nix
+++ b/pkgs/by-name/li/libgpiod/package.nix
@@ -26,7 +26,7 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
-    "--enable-tools=${if enable-tools then "yes" else "no"}"
+    "--enable-tools=${lib.boolToYesNo enable-tools}"
     "--enable-bindings-cxx"
   ];
 
diff --git a/pkgs/by-name/li/libgpiod_1/package.nix b/pkgs/by-name/li/libgpiod_1/package.nix
index f1c4908a2683..39aa5b933d01 100644
--- a/pkgs/by-name/li/libgpiod_1/package.nix
+++ b/pkgs/by-name/li/libgpiod_1/package.nix
@@ -41,7 +41,7 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
-    "--enable-tools=${if enable-tools then "yes" else "no"}"
+    "--enable-tools=${lib.boolToYesNo enable-tools}"
     "--enable-bindings-cxx"
     "--prefix=${placeholder "out"}"
   ]
diff --git a/pkgs/by-name/mo/moc/package.nix b/pkgs/by-name/mo/moc/package.nix
index ee093e43eb4c..676b435661ba 100644
--- a/pkgs/by-name/mo/moc/package.nix
+++ b/pkgs/by-name/mo/moc/package.nix
@@ -147,7 +147,7 @@ stdenv.mkDerivation {
     # Misc
     (lib.withFeature curlSupport "curl")
     (lib.withFeature samplerateSupport "samplerate")
-    ("--enable-debug=" + (if withDebug then "yes" else "no"))
+    "--enable-debug=${lib.boolToYesNo withDebug}"
     "--disable-cache"
     "--without-rcc"
   ];
diff --git a/pkgs/by-name/mo/motif/package.nix b/pkgs/by-name/mo/motif/package.nix
index c06b6c1e062c..92bd4eafae1b 100644
--- a/pkgs/by-name/mo/motif/package.nix
+++ b/pkgs/by-name/mo/motif/package.nix
@@ -119,7 +119,7 @@ stdenv.mkDerivation rec {
 
   # provide correct configure answers for cross builds
   configureFlags = [
-    "ac_cv_func_setpgrp_void=${if stdenv.hostPlatform.isBSD then "no" else "yes"}"
+    "ac_cv_func_setpgrp_void=${lib.boolToYesNo (!stdenv.hostPlatform.isBSD)}"
   ];
 
   env = lib.optionalAttrs stdenv.cc.isClang {
diff --git a/pkgs/by-name/mu/mupdf/package.nix b/pkgs/by-name/mu/mupdf/package.nix
index 1d3b8cea5f99..82447b34a4c5 100644
--- a/pkgs/by-name/mu/mupdf/package.nix
+++ b/pkgs/by-name/mu/mupdf/package.nix
@@ -282,7 +282,7 @@ stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
-  env.USE_SONAME = if (stdenv.hostPlatform.isDarwin) then "no" else "yes";
+  env.USE_SONAME = lib.boolToYesNo (!stdenv.hostPlatform.isDarwin);
 
   passthru = {
     tests = {
diff --git a/pkgs/by-name/ne/networkmanager-fortisslvpn/package.nix b/pkgs/by-name/ne/networkmanager-fortisslvpn/package.nix
index c03e224044a2..578632ad42b3 100644
--- a/pkgs/by-name/ne/networkmanager-fortisslvpn/package.nix
+++ b/pkgs/by-name/ne/networkmanager-fortisslvpn/package.nix
@@ -63,8 +63,8 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
-    "--with-gnome=${if withGnome then "yes" else "no"}"
-    "--with-gtk4=${if withGnome then "yes" else "no"}"
+    "--with-gnome=${lib.boolToYesNo withGnome}"
+    "--with-gtk4=${lib.boolToYesNo withGnome}"
     "--localstatedir=/var"
     "--enable-absolute-paths"
   ];
diff --git a/pkgs/by-name/ne/networkmanager-iodine/package.nix b/pkgs/by-name/ne/networkmanager-iodine/package.nix
index 423a68a9392b..c32c8d3ac34d 100644
--- a/pkgs/by-name/ne/networkmanager-iodine/package.nix
+++ b/pkgs/by-name/ne/networkmanager-iodine/package.nix
@@ -53,7 +53,7 @@ stdenv.mkDerivation {
   ];
 
   configureFlags = [
-    "--with-gnome=${if withGnome then "yes" else "no"}"
+    "--with-gnome=${lib.boolToYesNo withGnome}"
     "--localstatedir=/" # needed for the management socket under /run/NetworkManager
     "--enable-absolute-paths"
   ];
diff --git a/pkgs/by-name/ne/networkmanager-l2tp/package.nix b/pkgs/by-name/ne/networkmanager-l2tp/package.nix
index ddb1a9ea489d..3b2a3830d5de 100644
--- a/pkgs/by-name/ne/networkmanager-l2tp/package.nix
+++ b/pkgs/by-name/ne/networkmanager-l2tp/package.nix
@@ -62,8 +62,8 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
-    "--with-gnome=${if withGnome then "yes" else "no"}"
-    "--with-gtk4=${if withGnome then "yes" else "no"}"
+    "--with-gnome=${lib.boolToYesNo withGnome}"
+    "--with-gtk4=${lib.boolToYesNo withGnome}"
     "--localstatedir=/var"
     "--enable-absolute-paths"
   ];
diff --git a/pkgs/by-name/ne/networkmanager-openconnect/package.nix b/pkgs/by-name/ne/networkmanager-openconnect/package.nix
index 2fa483df360e..d9bf1c519342 100644
--- a/pkgs/by-name/ne/networkmanager-openconnect/package.nix
+++ b/pkgs/by-name/ne/networkmanager-openconnect/package.nix
@@ -60,8 +60,8 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
-    "--with-gnome=${if withGnome then "yes" else "no"}"
-    "--with-gtk4=${if withGnome then "yes" else "no"}"
+    "--with-gnome=${lib.boolToYesNo withGnome}"
+    "--with-gtk4=${lib.boolToYesNo withGnome}"
     "--enable-absolute-paths"
   ];
 
diff --git a/pkgs/by-name/ne/networkmanager-openvpn/package.nix b/pkgs/by-name/ne/networkmanager-openvpn/package.nix
index fc777d2e7a77..8ea6dd63f8db 100644
--- a/pkgs/by-name/ne/networkmanager-openvpn/package.nix
+++ b/pkgs/by-name/ne/networkmanager-openvpn/package.nix
@@ -56,8 +56,8 @@ stdenv.mkDerivation (finalAttrs: {
   ];
 
   configureFlags = [
-    "--with-gnome=${if withGnome then "yes" else "no"}"
-    "--with-gtk4=${if withGnome then "yes" else "no"}"
+    "--with-gnome=${lib.boolToYesNo withGnome}"
+    "--with-gtk4=${lib.boolToYesNo withGnome}"
     "--localstatedir=/" # needed for the management socket under /run/NetworkManager
     "--enable-absolute-paths"
   ];
diff --git a/pkgs/by-name/ne/networkmanager-sstp/package.nix b/pkgs/by-name/ne/networkmanager-sstp/package.nix
index fb44c80c5e31..b881ddf0c756 100644
--- a/pkgs/by-name/ne/networkmanager-sstp/package.nix
+++ b/pkgs/by-name/ne/networkmanager-sstp/package.nix
@@ -59,8 +59,8 @@ stdenv.mkDerivation rec {
   '';
 
   configureFlags = [
-    "--with-gnome=${if withGnome then "yes" else "no"}"
-    "--with-gtk4=${if withGnome then "yes" else "no"}"
+    "--with-gnome=${lib.boolToYesNo withGnome}"
+    "--with-gtk4=${lib.boolToYesNo withGnome}"
     "--with-pppd-plugin-dir=$(out)/lib/pppd/2.5.0"
     "--enable-absolute-paths"
   ];
diff --git a/pkgs/by-name/ne/networkmanager-vpnc/package.nix b/pkgs/by-name/ne/networkmanager-vpnc/package.nix
index e5eab9609e70..06c49313d36e 100644
--- a/pkgs/by-name/ne/networkmanager-vpnc/package.nix
+++ b/pkgs/by-name/ne/networkmanager-vpnc/package.nix
@@ -52,8 +52,8 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
-    "--with-gnome=${if withGnome then "yes" else "no"}"
-    "--with-gtk4=${if withGnome then "yes" else "no"}"
+    "--with-gnome=${lib.boolToYesNo withGnome}"
+    "--with-gtk4=${lib.boolToYesNo withGnome}"
     "--enable-absolute-paths"
   ];
 
diff --git a/pkgs/by-name/op/openmpi/package.nix b/pkgs/by-name/op/openmpi/package.nix
index 2984c4c035d9..4bd744c5f5d3 100644
--- a/pkgs/by-name/op/openmpi/package.nix
+++ b/pkgs/by-name/op/openmpi/package.nix
@@ -58,7 +58,7 @@ stdenv.mkDerivation (finalAttrs: {
           substituteInPlace configure \
             --replace-fail \
               ompi_cv_op_avx_check_${option}=yes \
-              ompi_cv_op_avx_check_${option}=${if val then "yes" else "no"}
+              ompi_cv_op_avx_check_${option}=${lib.boolToYesNo val}
         ''
       ))
       (lib.concatStringsSep "\n")
diff --git a/pkgs/by-name/pc/pciutils/package.nix b/pkgs/by-name/pc/pciutils/package.nix
index 3aa99cd6634a..b3a0d2b91357 100644
--- a/pkgs/by-name/pc/pciutils/package.nix
+++ b/pkgs/by-name/pc/pciutils/package.nix
@@ -36,7 +36,7 @@ stdenv.mkDerivation rec {
   enableParallelBuilding = true;
 
   makeFlags = [
-    "SHARED=${if static then "no" else "yes"}"
+    "SHARED=${lib.boolToYesNo (!static)}"
     "PREFIX=\${out}"
     "STRIP="
     "HOST=${stdenv.hostPlatform.system}"
diff --git a/pkgs/by-name/sh/shadow/package.nix b/pkgs/by-name/sh/shadow/package.nix
index 719bfb4fb1ff..72681d81eae0 100644
--- a/pkgs/by-name/sh/shadow/package.nix
+++ b/pkgs/by-name/sh/shadow/package.nix
@@ -86,7 +86,7 @@ stdenv.mkDerivation rec {
 
   # `AC_FUNC_SETPGRP' is not cross-compilation capable.
   preConfigure = ''
-    export ac_cv_func_setpgrp_void=${if stdenv.hostPlatform.isBSD then "no" else "yes"}
+    export ac_cv_func_setpgrp_void=${lib.boolToYesNo (!stdenv.hostPlatform.isBSD)}
     export shadow_cv_logdir=/var/log
   '';
 
diff --git a/pkgs/by-name/tp/tpm2-pkcs11/package.nix b/pkgs/by-name/tp/tpm2-pkcs11/package.nix
index 233f578d6596..aa5c17d283aa 100644
--- a/pkgs/by-name/tp/tpm2-pkcs11/package.nix
+++ b/pkgs/by-name/tp/tpm2-pkcs11/package.nix
@@ -87,7 +87,7 @@ chosenStdenv.mkDerivation (finalAttrs: {
     (lib.enableFeature finalAttrs.doCheck "integration")
 
     # Strangely, it uses --with-fapi=yes|no instead of a normal configure flag.
-    "--with-fapi=${if fapiSupport then "yes" else "no"}"
+    "--with-fapi=${lib.boolToYesNo fapiSupport}"
   ]
   ++ lib.optionals enableFuzzing [
     "--enable-fuzzing"
diff --git a/pkgs/by-name/w3/w3m/package.nix b/pkgs/by-name/w3/w3m/package.nix
index 4cb3648a56c5..c9d00588502a 100644
--- a/pkgs/by-name/w3/w3m/package.nix
+++ b/pkgs/by-name/w3/w3m/package.nix
@@ -110,7 +110,7 @@ stdenv.mkDerivation (finalAttrs: {
     "CFLAGS=-std=gnu17"
   ]
   ++ lib.optionals (stdenv.buildPlatform != stdenv.hostPlatform) [
-    "ac_cv_func_setpgrp_void=${if stdenv.hostPlatform.isBSD then "no" else "yes"}"
+    "ac_cv_func_setpgrp_void=${lib.boolToYesNo (!stdenv.hostPlatform.isBSD)}"
   ]
   ++ lib.optional graphicsSupport "--enable-image=${lib.optionalString x11Support "x11,"}fb"
   ++ lib.optional (graphicsSupport && !x11Support) "--without-x";
diff --git a/pkgs/development/ada-modules/gnatcoll/core.nix b/pkgs/development/ada-modules/gnatcoll/core.nix
index 6cd55e28c0bb..015c2e54e276 100644
--- a/pkgs/development/ada-modules/gnatcoll/core.nix
+++ b/pkgs/development/ada-modules/gnatcoll/core.nix
@@ -63,8 +63,8 @@ stdenv.mkDerivation rec {
     "PROCESSORS=$(NIX_BUILD_CORES)"
     # confusingly, for gprbuild --target is autoconf --host
     "TARGET=${stdenv.hostPlatform.config}"
-    "GNATCOLL_MINIMAL_ONLY=${if !enableGnatcollCore then "yes" else "no"}"
-    "GNATCOLL_PROJECTS=${if enableGnatcollProjects then "yes" else "no"}"
+    "GNATCOLL_MINIMAL_ONLY=${lib.boolToYesNo (!enableGnatcollCore)}"
+    "GNATCOLL_PROJECTS=${lib.boolToYesNo enableGnatcollProjects}"
   ];
 
   passthru.tests = {
diff --git a/pkgs/development/ada-modules/gpr2/default.nix b/pkgs/development/ada-modules/gpr2/default.nix
index 11c6006884f5..7448d251a692 100644
--- a/pkgs/development/ada-modules/gpr2/default.nix
+++ b/pkgs/development/ada-modules/gpr2/default.nix
@@ -32,7 +32,7 @@ stdenv.mkDerivation rec {
   makeFlags = [
     "prefix=$(out)"
     "PROCESSORS=$(NIX_BUILD_CORES)"
-    "ENABLE_SHARED=${if enableShared then "yes" else "no"}"
+    "ENABLE_SHARED=${lib.boolToYesNo enableShared}"
     "GPR2_BUILD=release"
   ]
   ++ lib.optionals (gpr2kbdir != null) [
diff --git a/pkgs/development/ada-modules/gprbuild/default.nix b/pkgs/development/ada-modules/gprbuild/default.nix
index b6f4a32fb441..c8d530466ca7 100644
--- a/pkgs/development/ada-modules/gprbuild/default.nix
+++ b/pkgs/development/ada-modules/gprbuild/default.nix
@@ -31,7 +31,7 @@ stdenv.mkDerivation {
   ];
 
   makeFlags = [
-    "ENABLE_SHARED=${if stdenv.hostPlatform.isStatic then "no" else "yes"}"
+    "ENABLE_SHARED=${lib.boolToYesNo (!stdenv.hostPlatform.isStatic)}"
     "PROCESSORS=$(NIX_BUILD_CORES)"
     # confusingly, for gprbuild --target is autoconf --host
     "TARGET=${stdenv.hostPlatform.config}"
diff --git a/pkgs/development/interpreters/python/cpython/default.nix b/pkgs/development/interpreters/python/cpython/default.nix
index 58a2a5c4e2e6..51f9a544146c 100644
--- a/pkgs/development/interpreters/python/cpython/default.nix
+++ b/pkgs/development/interpreters/python/cpython/default.nix
@@ -516,8 +516,8 @@ stdenv.mkDerivation (finalAttrs: {
     "ac_cv_have_size_t_format=yes"
     "ac_cv_computed_gotos=yes"
     # Both fail when building for windows, normally configure checks this by itself but on other platforms this is set to yes always.
-    "ac_cv_file__dev_ptmx=${if stdenv.hostPlatform.isWindows then "no" else "yes"}"
-    "ac_cv_file__dev_ptc=${if stdenv.hostPlatform.isWindows then "no" else "yes"}"
+    "ac_cv_file__dev_ptmx=${lib.boolToYesNo (!stdenv.hostPlatform.isWindows)}"
+    "ac_cv_file__dev_ptc=${lib.boolToYesNo (!stdenv.hostPlatform.isWindows)}"
   ]
   ++ optionals (stdenv.hostPlatform != stdenv.buildPlatform && pythonAtLeast "3.11") [
     "--with-build-python=${pythonOnBuildForHostInterpreter}"
diff --git a/pkgs/development/libraries/libgda/5.x.nix b/pkgs/development/libraries/libgda/5.x.nix
index 0761542379d3..ff40c3ccf86e 100644
--- a/pkgs/development/libraries/libgda/5.x.nix
+++ b/pkgs/development/libraries/libgda/5.x.nix
@@ -78,15 +78,15 @@ stdenv.mkDerivation rec {
   ];
 
   configureFlags = [
-    "--with-mysql=${if mysqlSupport then "yes" else "no"}"
-    "--with-postgres=${if postgresSupport then "yes" else "no"}"
+    "--with-mysql=${lib.boolToYesNo mysqlSupport}"
+    "--with-postgres=${lib.boolToYesNo postgresSupport}"
 
     # macOS builds use the sqlite source code that comes with libgda,
     # as opposed to using the system or brewed sqlite3, which is not supported on macOS,
     # as mentioned in https://github.com/GNOME/libgda/blob/95eeca4b0470f347c645a27f714c62aa6e59f820/libgda/sqlite/README#L31,
     # which references the paper https://web.archive.org/web/20100610151539/http://lattice.umiacs.umd.edu/files/functions_tr.pdf
     # See also https://github.com/Homebrew/homebrew-core/blob/104f9ecd02854a82372b64d63d41356555378a52/Formula/libgda.rb
-    "--enable-system-sqlite=${if stdenv.hostPlatform.isDarwin then "no" else "yes"}"
+    "--enable-system-sqlite=${lib.boolToYesNo (!stdenv.hostPlatform.isDarwin)}"
   ];
 
   env.NIX_CFLAGS_COMPILE = "-Wno-error=incompatible-pointer-types";
diff --git a/pkgs/development/tools/protoc-gen-grpc-web/default.nix b/pkgs/development/tools/protoc-gen-grpc-web/default.nix
index 61e9c252c12c..357d1d9a7272 100644
--- a/pkgs/development/tools/protoc-gen-grpc-web/default.nix
+++ b/pkgs/development/tools/protoc-gen-grpc-web/default.nix
@@ -26,7 +26,7 @@ stdenv.mkDerivation (finalAttrs: {
 
   makeFlags = [
     "PREFIX=$(out)"
-    "STATIC=${if isStatic then "yes" else "no"}"
+    "STATIC=${lib.boolToYesNo isStatic}"
   ];
 
   doCheck = true;
diff --git a/pkgs/games/quake2/yquake2/default.nix b/pkgs/games/quake2/yquake2/default.nix
index 749147859273..1646cb3163c3 100644
--- a/pkgs/games/quake2/yquake2/default.nix
+++ b/pkgs/games/quake2/yquake2/default.nix
@@ -14,8 +14,6 @@
 }:
 
 let
-  mkFlag = b: if b then "yes" else "no";
-
   games = import ./games.nix { inherit stdenv lib fetchFromGitHub; };
 
   wrapper = import ./wrapper.nix {
@@ -58,7 +56,7 @@ let
     ++ lib.optional openalSupport openal;
 
     makeFlags = [
-      "WITH_OPENAL=${mkFlag openalSupport}"
+      "WITH_OPENAL=${lib.boolToYesNo openalSupport}"
       "WITH_SYSTEMWIDE=yes"
       "WITH_SYSTEMDIR=$\{out}/share/games/quake2"
     ];
diff --git a/pkgs/os-specific/bsd/freebsd/pkgs/sys/package.nix b/pkgs/os-specific/bsd/freebsd/pkgs/sys/package.nix
index 9c93d416f6c0..3dbfe3d9c284 100644
--- a/pkgs/os-specific/bsd/freebsd/pkgs/sys/package.nix
+++ b/pkgs/os-specific/bsd/freebsd/pkgs/sys/package.nix
@@ -70,7 +70,7 @@ let
   // (lib.flip lib.mapAttrs' extraFlags (
     name: value: {
       name = "MK_${lib.toUpper name}";
-      value = if value then "yes" else "no";
+      value = lib.boolToYesNo value;
     }
   ));
 in
diff --git a/pkgs/shells/bash/5.nix b/pkgs/shells/bash/5.nix
index 08b4e4bff2fc..0ca4ca768b5d 100644
--- a/pkgs/shells/bash/5.nix
+++ b/pkgs/shells/bash/5.nix
@@ -103,7 +103,7 @@ lib.warnIf (withDocs != null)
       # default is fine for static linking on Linux (weak symbols?) but
       # not with BSDs, when it does clash with the regular `getenv`.
       "bash_cv_getenv_redef=${
-        if !(with stdenv.hostPlatform; isStatic && (isOpenBSD || isFreeBSD)) then "yes" else "no"
+        lib.boolToYesNo (!(with stdenv.hostPlatform; isStatic && (isOpenBSD || isFreeBSD)))
       }"
     ]
     ++ lib.optionals stdenv.hostPlatform.isCygwin [
diff --git a/pkgs/tools/nix/info/default.nix b/pkgs/tools/nix/info/default.nix
index be5b75282101..00e6821ce7bd 100644
--- a/pkgs/tools/nix/info/default.nix
+++ b/pkgs/tools/nix/info/default.nix
@@ -23,7 +23,7 @@ stdenv.mkDerivation {
     ]
     ++ (lib.optionals stdenv.hostPlatform.isDarwin [ darwin.DarwinTools ])
   );
-  is_darwin = if stdenv.hostPlatform.isDarwin then "yes" else "no";
+  is_darwin = lib.boolToYesNo stdenv.hostPlatform.isDarwin;
 
   sandboxtest = ./sandbox.nix;
   relaxedsandboxtest = ./relaxedsandbox.nix;