diff --git a/pkgs/development/interpreters/tcl/default.nix b/pkgs/development/interpreters/tcl/default.nix
index 5de7bc90584..d6e6b9df71b 100644
--- a/pkgs/development/interpreters/tcl/default.nix
+++ b/pkgs/development/interpreters/tcl/default.nix
@@ -1,10 +1,10 @@
 {stdenv, fetchurl}:
 
 stdenv.mkDerivation {
-  name = "tcl-8.4.11";
+  name = "tcl-8.4.13";
   builder = ./builder.sh;
   src = fetchurl {
-    url = http://nix.cs.uu.nl/dist/tarballs/tcl8.4.11-src.tar.gz;
-    md5 = "629dfea34e4087eb4683f834060abb63";
+    url = http://heanet.dl.sourceforge.net/sourceforge/tcl/tcl8.4.13-src.tar.gz;
+    md5 = "c6b655ad5db095ee73227113220c0523";
   };
 }