diff --git a/Dist.cabal b/Dist.cabal
--- a/Dist.cabal
+++ b/Dist.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                Dist
-version:             0.4.1.0
+version:             0.4.2
 synopsis:            A Haskell library for probability distributions
 description:         This library provides a data structure and associated functions for representing discrete probability distributions.
 homepage:            https://github.com/wyager/Dist
@@ -24,7 +24,7 @@
   exposed-modules:     Numeric.Probability.Distribution
   -- other-modules:
   other-extensions:    BangPatterns, GeneralizedNewtypeDeriving
-  build-depends:       base >=4.7 && <= 4.9.1.0, MonadRandom >=0.3, containers >=0.5
+  build-depends:       base ==4.12.*, MonadRandom ==0.5.*, containers == 0.6.*
   hs-source-dirs:      src
   default-language:    Haskell2010
 
@@ -32,6 +32,6 @@
   type: exitcode-stdio-1.0
   main-is: Numeric/Probability/Distribution/Test.hs
   other-extensions:    BangPatterns, GeneralizedNewtypeDeriving
-  build-depends:       base >=4.7 && <= 4.9.1.0, MonadRandom >=0.3, containers >=0.5
+  build-depends:       base ==4.12.*, MonadRandom ==0.5.*, containers == 0.6.*
   hs-source-dirs:      src
   default-language:    Haskell2010