diff --git a/pkgs/by-name/t4/t4kcommon/package.nix b/pkgs/by-name/t4/t4kcommon/package.nix
index 17ee971bc351..2cfc91f0b4cf 100644
--- a/pkgs/by-name/t4/t4kcommon/package.nix
+++ b/pkgs/by-name/t4/t4kcommon/package.nix
@@ -2,7 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
-  fetchurl,
+  fetchpatch,
   cmake,
   pkg-config,
   SDL,
@@ -28,9 +28,9 @@ stdenv.mkDerivation rec {
 
   patches = [
     # patch from debian to support libpng16 instead of libpng12
-    (fetchurl {
+    (fetchpatch {
       url = "https://salsa.debian.org/tux4kids-pkg-team/t4kcommon/raw/f7073fa384f5a725139f54844e59b57338b69dc7/debian/patches/libpng16.patch";
-      sha256 = "1lcpkdy5gvxgljg1vkrxych74amq0gramb1snj2831dam48is054";
+      hash = "sha256-auQ8VvOyvLE1PD2dfeHZJV+MzIt1OtUa7OcOqsXTAYI=";
     })
   ];