diff --git a/build-constraints.yaml b/build-constraints.yaml
index 8959713f..f8fbbee5 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3231,6 +3231,9 @@ packages:
         # https://github.com/fpco/stackage/issues/2562
         - trifecta < 1.7
 
+        # https://github.com/jaspervdj/hakyll/issues/540
+        - hakyll < 4.9.5.1
+
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of