diff --git a/lattices.cabal b/lattices.cabal
--- a/lattices.cabal
+++ b/lattices.cabal
@@ -1,5 +1,5 @@
 Name:               lattices
-Version:            1.2
+Version:            1.2.1
 Cabal-Version:      >= 1.2
 Category:           Math
 Synopsis:           Fine-grained library for constructing and manipulating lattices
@@ -18,4 +18,4 @@
                          Algebra.PartialOrd
                          
         Build-Depends:   base >= 3 && < 5,
-                         containers >= 0.3 && < 0.4
+                         containers >= 0.3 && < 0.5