diff --git a/build-constraints.yaml b/build-constraints.yaml
index 7c561f66..70fa0e9b 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -6794,7 +6794,7 @@ packages:
       - burrito < 2.0.0.0
 
       # https://github.com/commercialhaskell/stackage/issues/6393
-      - flow < 2.0.0.0
+      - flow < 2.0.0.0 # blocked by shikensu through aeson-2.0
 
       # https://github.com/commercialhaskell/stackage/issues/6395
       - wuss < 2.0