diff --git a/som.cabal b/som.cabal
--- a/som.cabal
+++ b/som.cabal
@@ -1,5 +1,5 @@
 name: som
-version: 9.0.2
+version: 9.0.3
 cabal-version: >=1.10
 build-type: Simple
 license: BSD3
@@ -56,11 +56,11 @@
     main-is: Main.hs
     build-depends:
         assert >=0.0.1.2 && <0.1,
-        base >=4.9.1.0 && <4.10,
+        base ==4.9.*,
         test-framework-quickcheck2 >=0.3.0.3 && <0.4,
         QuickCheck >=2.9.2 && <2.10,
         test-framework >=0.8.1.1 && <0.9,
-        som >=9.0.2 && <9.1,
+        som >=9.0.3 && <9.1,
         containers >=0.5.7.1 && <0.6,
         grid >=7.8.8 && <7.9,
         MonadRandom >=0.5.1 && <0.6,