diff --git a/build-constraints.yaml b/build-constraints.yaml
index 476fe63d..0fb28982 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -1209,6 +1209,9 @@ packages:
         # https://github.com/fpco/stackage/issues/682
         - vector < 0.11
 
+        # https://github.com/fpco/stackage/issues/684
+        - cmark < 0.4
+
 # Package flags are applied to individual packages, and override the values of
 # global-flags
 package-flags: