diff --git a/logict.cabal b/logict.cabal
--- a/logict.cabal
+++ b/logict.cabal
@@ -1,5 +1,5 @@
 Name:                   logict
-Version:                0.4.1
+Version:                0.4.2
 Description:            A continuation-based, backtracking, logic programming monad.
                         An adaptation of the two-continuation implementation found
                         in the paper "Backtracking, Interleaving, and Terminating
@@ -16,7 +16,7 @@
 
 Stability:              Experimental
 Tested-With:            GHC
-Build-Depends:          base >=2 && < 5, mtl>=1.0.1 && <1.2
+Build-Depends:          base >=2 && < 5, mtl>=1.0.1 && <2.1
 Build-Type:             Simple
 
 Exposed-Modules:        Control.Monad.Logic,