diff --git a/pkgs/tools/text/qshowdiff/default.nix b/pkgs/tools/text/qshowdiff/default.nix
index 761a498bcfb..e3970c05902 100644
--- a/pkgs/tools/text/qshowdiff/default.nix
+++ b/pkgs/tools/text/qshowdiff/default.nix
@@ -14,7 +14,7 @@ stdenv.mkDerivation rec {
 
   configurePhase = ''
     mkdir -p $out/{bin,man/man1}
-    makeFlags="PREFIX=$out"
+    makeFlags="PREFIX=$out CC=$CXX"
   '';
 
   meta = {