diff --git a/pkgs/applications/science/math/cntk/default.nix b/pkgs/applications/science/math/cntk/default.nix
index 89ed0582b37e..bef695fc650a 100644
--- a/pkgs/applications/science/math/cntk/default.nix
+++ b/pkgs/applications/science/math/cntk/default.nix
@@ -95,5 +95,6 @@ in stdenv.mkDerivation rec {
     description = "An open source deep-learning toolkit";
     license = if onebitSGDSupport then licenses.unfreeRedistributable else licenses.mit;
     maintainers = with maintainers; [ abbradar ];
+    broken = true; # Never succeeded to build.
   };
 }