diff --git a/pkgs/development/libraries/tk/8.6.nix b/pkgs/development/libraries/tk/8.6.nix
index c8f4efa7f7aca..84028762dbba9 100644
--- a/pkgs/development/libraries/tk/8.6.nix
+++ b/pkgs/development/libraries/tk/8.6.nix
@@ -8,7 +8,7 @@ callPackage ./generic.nix (args // {
 
   src = fetchurl {
     url = "mirror://sourceforge/tcl/tk${tcl.version}-src.tar.gz";
-    sha256 = "sha256-LmX6BpojNlRAo8VsVWuGc7XjKig4ANjZslfj9YTOBnU=";
+    sha256 = "sha256-VQlp81N5+VKzAg86t7ndW/0Rwe98m3xqdfXEmsp5P+w=";
   };
 
   patches = [