diff --git a/build-constraints.yaml b/build-constraints.yaml
index f3bf9a58..df07c2f2 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -688,7 +688,7 @@ packages:
 
         - alex
         - async
-        - base16-bytestring
+        - base16-bytestring < 1 # https://github.com/commercialhaskell/stackage/issues/5649
         - csv-conduit < 0 # ghc 8.10
         - executable-hash < 0 # via cryptohash
         - executable-path