diff --git a/pkgs/applications/editors/wily/default.nix b/pkgs/applications/editors/wily/default.nix
index 74d0bc156758..0e883a51210a 100644
--- a/pkgs/applications/editors/wily/default.nix
+++ b/pkgs/applications/editors/wily/default.nix
@@ -11,7 +11,11 @@ stdenv.mkDerivation rec {
 
   buildInputs = [ libX11 libXt ];
 
-  configureFlags = [ "--prefix=$(out)" ];
+  env.NIX_CFLAGS_COMPILE = toString (lib.optionals stdenv.cc.isClang [
+    "-Wno-error=implicit-int"
+    "-Wno-error=implicit-function-declaration"
+    "-Wno-error=incompatible-function-pointer-types"
+  ]);
 
   preInstall = ''
     mkdir -p $out/bin