diff --git a/pkgs/development/libraries/ace/default.nix b/pkgs/development/libraries/ace/default.nix
index 42988e334b07..230a7e64dff3 100644
--- a/pkgs/development/libraries/ace/default.nix
+++ b/pkgs/development/libraries/ace/default.nix
@@ -2,11 +2,11 @@
 
 stdenv.mkDerivation rec {
   name = "ace-${version}";
-  version = "6.4.3";
+  version = "6.4.6";
 
   src = fetchurl {
     url = "http://download.dre.vanderbilt.edu/previous_versions/ACE-${version}.tar.bz2";
-    sha256 = "07dvpi3abmjvg7m0aak4x82aj8cvw5zl2cqj525wd3fl6y0pn3mq";
+    sha256 = "0xvdwk2505s615fgsy6g33ncxx70vszqspx0bg6lm8hfd3hb4qyj";
   };
 
   enableParallelBuilding = true;