diff --git a/deferred-folds.cabal b/deferred-folds.cabal
--- a/deferred-folds.cabal
+++ b/deferred-folds.cabal
@@ -1,5 +1,5 @@
 name: deferred-folds
-version: 0.9.9
+version: 0.9.9.1
 category: Folding
 synopsis: Abstractions over deferred folds
 description:
@@ -39,7 +39,7 @@
   build-depends:
     base >=4.9 && <5,
     bytestring >=0.10 && <0.11,
-    containers >=0.5 && <0.6,
+    containers >=0.5 && <0.7,
     foldl >=1 && <2,
     hashable >=1 && <2,
     primitive >=0.6.4 && <0.7,