diff --git a/pkgs/development/libraries/grpc/default.nix b/pkgs/development/libraries/grpc/default.nix
index e568ea9eb65..f4145c85199 100644
--- a/pkgs/development/libraries/grpc/default.nix
+++ b/pkgs/development/libraries/grpc/default.nix
@@ -26,7 +26,7 @@ stdenv.mkDerivation rec {
     rm -vf BUILD
   '';
 
-  NIX_CFLAGS_COMPILE = "-Wno-error=unknown-warning-option";
+  NIX_CFLAGS_COMPILE = stdenv.lib.optionalString stdenv.cc.isClang "-Wno-error=unknown-warning-option";
 
   enableParallelBuilds = true;