diff --git a/build-constraints.yaml b/build-constraints.yaml
index e001ec35..668b9d3f 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -2508,6 +2508,9 @@ packages:
 
         # https://github.com/fpco/stackage/issues/1733
         - tagged < 0.8.5
+
+        # https://github.com/fpco/stackage/issues/1734
+        - haskell-src-exts < 1.18
 # end of packages