diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index d1836850329..3bc24631e12 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -10572,6 +10572,7 @@ in {
       license = licenses.bsd2;
       platforms = platforms.all;
       homepage = "http://jparyani.github.io/pycapnp/index.html";
+      broken = true; # 2018-04-11
     };
   };