diff --git a/Stackage/Config.hs b/Stackage/Config.hs
index e2665ac3..eee3e678 100644
--- a/Stackage/Config.hs
+++ b/Stackage/Config.hs
@@ -205,6 +205,8 @@ defaultExpectedFailures ghcVer = execWriter $ do
 
     -- For some unknown reason, doctest has trouble on GHC 7.6. This only
     -- happens during a Stackage test.
+    --
+    -- See: http://www.reddit.com/r/haskell/comments/2go92u/beginner_error_messages_in_c_vs_haskell/cklaspk
     when (ghcVer == GhcMajorVersion 7 8) $ add "http-types"
   where
     add = tell . singleton . PackageName