diff --git a/pkgs/applications/misc/ksmoothdock/default.nix b/pkgs/applications/misc/ksmoothdock/default.nix
index 7325c85dbd4..80c46bd9c16 100644
--- a/pkgs/applications/misc/ksmoothdock/default.nix
+++ b/pkgs/applications/misc/ksmoothdock/default.nix
@@ -18,6 +18,12 @@ mkDerivation rec {
     sha256 = "sha256-hO7xgjFMFrEhQs3oc2peFTjSVEDsl7Ma/TeVybEZMEk=";
   };
 
+  # Upstream seems dead and there are new deprecation warnings in KF5.100
+  # Remember, kids: friends don't let friends build with -Werror
+  postPatch = ''
+    substituteInPlace src/CMakeLists.txt --replace "-Werror" ""
+  '';
+
   nativeBuildInputs = [ cmake extra-cmake-modules ];
 
   buildInputs = [ kactivities qtbase ];