diff --git a/pkgs/development/tcl-modules/by-name/tc/tclmagick/package.nix b/pkgs/development/tcl-modules/by-name/tc/tclmagick/package.nix
index cbfe979ac79a..34423b623f79 100644
--- a/pkgs/development/tcl-modules/by-name/tc/tclmagick/package.nix
+++ b/pkgs/development/tcl-modules/by-name/tc/tclmagick/package.nix
@@ -7,16 +7,16 @@
   tk,
 }:
 
-mkTclDerivation rec {
+mkTclDerivation (finalAttrs: {
   pname = "tclmagick";
   version = "1.3.43";
 
   src = fetchzip {
-    url = "mirror://sourceforge/graphicsmagick/GraphicsMagick-${version}.tar.xz";
+    url = "mirror://sourceforge/graphicsmagick/GraphicsMagick-${finalAttrs.version}.tar.xz";
     hash = "sha256-CpZztiBF0HqH4XWIAyE9IbZVpBcgrDzyASv47wTneQ0=";
   };
 
-  sourceRoot = src.name + "/TclMagick";
+  sourceRoot = finalAttrs.src.name + "/TclMagick";
 
   buildInputs = [
     graphicsmagick
@@ -37,4 +37,4 @@ mkTclDerivation rec {
     maintainers = with lib.maintainers; [ fgaz ];
     broken = tcl.isTcl9;
   };
-}
+})