diff --git a/pkgs/by-name/fr/freeswitch/package.nix b/pkgs/by-name/fr/freeswitch/package.nix
index 1b43feeca048..c80de735f401 100644
--- a/pkgs/by-name/fr/freeswitch/package.nix
+++ b/pkgs/by-name/fr/freeswitch/package.nix
@@ -159,17 +159,19 @@ stdenv.mkDerivation (finalAttrs: {
 
   enableParallelBuilding = true;
 
-  env.NIX_CFLAGS_COMPILE = toString [
-    "-Wno-error"
-    # https://github.com/signalwire/freeswitch/issues/2495
-    "-Wno-incompatible-pointer-types"
-  ];
+  env = {
+    NIX_CFLAGS_COMPILE = toString [
+      "-Wno-error"
+      # https://github.com/signalwire/freeswitch/issues/2495
+      "-Wno-incompatible-pointer-types"
+    ];
 
-  # Using c++14 because of build error
-  # gsm_at.h:94:32: error: ISO C++17 does not allow dynamic exception specifications
-  CXXFLAGS = "-std=c++14";
+    # Using c++14 because of build error
+    # gsm_at.h:94:32: error: ISO C++17 does not allow dynamic exception specifications
+    CXXFLAGS = "-std=c++14";
 
-  CFLAGS = "-D_ANSI_SOURCE";
+    CFLAGS = "-D_ANSI_SOURCE";
+  };
 
   hardeningDisable = [ "format" ];