diff --git a/build-constraints.yaml b/build-constraints.yaml
index 5c7bfef9..627e4fdb 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -7990,6 +7990,10 @@ packages:
         # https://github.com/commercialhaskell/stackage/issues/7506
         - postgresql-libpq < 0.11
         - postgresql-libpq-configure < 0.11
+
+        # https://github.com/commercialhaskell/stackage/issues/7527
+        - sydtest < 0.18
+
     # end of Stackage upper bounds
 # end of packages