diff --git a/build-constraints.yaml b/build-constraints.yaml
index 13924eaa..210590e5 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -808,7 +808,7 @@ packages:
 
         - time-manager
         - pantry
-        - mega-sdist
+        - mega-sdist < 0 # via aeson 2, https://github.com/commercialhaskell/stackage/issues/6453
         - http-download
         - hi-file-parser
         - rio-prettyprint