diff --git a/build-constraints.yaml b/build-constraints.yaml
index 5b9d2327..b86e9aeb 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -3761,6 +3761,8 @@ packages:
         - conduit-aeson
         - vector-stream
         - FailT
+        - mempack
+        - ImpSpec
 
     "Hans-Peter Deifel <hpd@hpdeifel.de> @hpdeifel":
         - hledger-iadd