diff --git a/pkgs/tools/misc/mdbtools/default.nix b/pkgs/tools/misc/mdbtools/default.nix
index 95d8f9e3bb7b..327b58d8d78b 100644
--- a/pkgs/tools/misc/mdbtools/default.nix
+++ b/pkgs/tools/misc/mdbtools/default.nix
@@ -16,6 +16,8 @@ stdenv.mkDerivation rec {
 
   configureFlags = [ "--disable-scrollkeeper" ];
 
+  env.NIX_CFLAGS_COMPILE = lib.optionalString stdenv.cc.isClang "-Wno-error=unused-but-set-variable";
+
   nativeBuildInputs = [
     pkg-config bison flex autoreconfHook txt2man which
   ];