diff --git a/pkgs/by-name/fb/fbpanel/package.nix b/pkgs/by-name/fb/fbpanel/package.nix
index bf62ae6d41da..2572ff5a00c1 100644
--- a/pkgs/by-name/fb/fbpanel/package.nix
+++ b/pkgs/by-name/fb/fbpanel/package.nix
@@ -49,8 +49,10 @@ stdenv.mkDerivation {
   '';
 
   makeFlags = [ "V=1" ];
-  NIX_CFLAGS_COMPILE = [
+
+  env.NIX_CFLAGS_COMPILE = toString [
     "-Wno-error"
+    "-Wno-error=incompatible-pointer-types" # not implied by -Wno-error
     "-I${gdk-pixbuf-xlib.dev}/include/gdk-pixbuf-2.0"
   ];