diff --git a/pkgs/by-name/x2/x265/package.nix b/pkgs/by-name/x2/x265/package.nix
index ddd820c145f5..eec407eeaf1b 100644
--- a/pkgs/by-name/x2/x265/package.nix
+++ b/pkgs/by-name/x2/x265/package.nix
@@ -87,7 +87,7 @@ stdenv.mkDerivation rec {
     ]
     # Clang does not support the endfunc directive so use GCC.
     ++ lib.optional (
-      stdenv.cc.isClang && !stdenv.targetPlatform.isDarwin
+      stdenv.cc.isClang && !stdenv.targetPlatform.isDarwin && !stdenv.targetPlatform.isFreeBSD
     ) "-DCMAKE_ASM_COMPILER=${gccStdenv.cc}/bin/${gccStdenv.cc.targetPrefix}gcc";
 
   cmakeStaticLibFlags =