diff --git a/build-constraints.yaml b/build-constraints.yaml
index 46fef054..56dedb02 100644
--- a/build-constraints.yaml
+++ b/build-constraints.yaml
@@ -8856,7 +8856,8 @@ packages:
         - zydiskell < 0 # tried zydiskell-0.2.0.0, but its *library* requires storable-record >=0.0.5 && < 0.0.6 and the snapshot contains storable-record-0.0.7
     # End of Library and exe bounds failures
 
-    "Stackage upper bounds": []
+    "Stackage upper bounds":
+        - base64 < 1.0 # https://github.com/commercialhaskell/stackage/issues/7279
     # end of Stackage upper bounds
 # end of packages