diff --git a/build-constraints.yaml b/build-constraints.yaml
index 4442da90..109ff083 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4836,6 +4836,10 @@ packages:
         # https://github.com/commercialhaskell/stackage/issues/4811
         - polysemy < 1.2.0.0
 
+        # https://github.com/commercialhaskell/stackage/issues/4812
+        - llvm-hs < 9
+        - llvm-hs-pure < 9
+
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of