diff --git a/build-constraints.yaml b/build-constraints.yaml
index ec1e0bbd..79f16065 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -4978,6 +4978,12 @@ packages:
       # https://github.com/commercialhaskell/stackage/issues/5623
       - http-api-data < 0.4.2
 
+      # https://github.com/commercialhaskell/stackage/issues/5632
+      - megaparsec < 9.0.0
+      # these don't explicitly require 9.0
+      - hspec-megaparsec < 2.2.0
+      - megaparsec-tests < 9.0.0
+
 # end of packages
 
 # Package flags are applied to individual packages, and override the values of