diff --git a/build-constraints.yaml b/build-constraints.yaml
index 1cec292f..63f4cd24 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -593,7 +593,7 @@ packages:
         - psqueues
         - websockets
         - websockets-snap
-        - hakyll
+        - hakyll # jaspervdj/hakyll#691
 
     "Sibi Prabakaran <sibi@psibi.in> @psibi":
         - download
@@ -838,7 +838,7 @@ packages:
         - gravatar
         - load-env
         - yesod-auth-oauth2
-        - yesod-markdown
+        - yesod-markdown < 0 # pbrisbin/yesod-markdown#65
         - yesod-paginator
 
     "Felipe Lessa <felipe.lessa@gmail.com> @meteficha":