diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,10 @@
+= Version 1.3.0.1, 2012-12-14 =
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+* Relax dependencies -- allow older versions of containers.
+A new flag is introduced, because there are dependencies
+between containers and deepseq versions: it is not possible
+to compile with deepseq >= 1.2 and containers < 0.4.2.
+
 = Version 1.3.0.0, 2012-12-11 =
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 * Add NFData instances.
diff --git a/hashmap.cabal b/hashmap.cabal
--- a/hashmap.cabal
+++ b/hashmap.cabal
@@ -1,5 +1,5 @@
 Name:                hashmap
-Version:             1.3.0.0
+Version:             1.3.0.1
 Synopsis:            Persistent containers Map and Set based on hashing.
 Description:         An implementation of persistent 'Map' and 'Set' containers
                      based on hashing. The implementation is build on
@@ -28,14 +28,19 @@
 Cabal-version:       >= 1.6
 Extra-source-files:  CHANGES
 
+Flag OldContainers
+  Description: Use old version of containers where NFData instances are provided by deepseq.
+  Default: False
+
 Library
-  Exposed-modules:   Data.HashMap, Data.HashSet
+  Exposed-modules: Data.HashMap, Data.HashSet
 
-  Build-depends:     base >= 4.0 && < 5,
-                     containers >= 0.4.2,
-                     deepseq >= 1.2,
-                     hashable >= 1.0
+  Build-depends: base >= 4.0 && < 5, hashable >= 1.0
+  if !flag(OldContainers)
+    Build-depends: containers >= 0.4.2, deepseq >= 1.2
+  else
+    Build-depends: containers >= 0.3, deepseq >= 1.0 && < 1.2
 
-  Extensions:        CPP
+  Extensions: CPP
   if impl(ghc)
-    Extensions:      StandaloneDeriving, DeriveDataTypeable
+    Extensions: StandaloneDeriving, DeriveDataTypeable