diff --git a/list-extras.cabal b/list-extras.cabal
--- a/list-extras.cabal
+++ b/list-extras.cabal
@@ -3,7 +3,7 @@
 ----------------------------------------------------------------
 
 Name:           list-extras
-Version:        0.4.0
+Version:        0.4.0.1
 Cabal-Version:  >= 1.2
 Build-Type:     Simple
 Stability:      stable
@@ -27,9 +27,9 @@
                 @Data.List.Extras.Foo@ namespace.
 
 
-Flag preludeInBase
+Flag base4
     Description: base-4.0 deprecated Prelude which is imported qualified
-    Default:     False
+    Default:     True
 
 Library
     Exposed-Modules: Prelude.Listless
@@ -37,10 +37,12 @@
                    , Data.List.Extras.Argmax
                    , Data.List.Extras.LazyLength
                    , Data.List.Extras.Pair
-    if flag(preludeInBase)
-        Build-Depends: base >= 4
+    if flag(base4)
+        -- TODO: What else do we need to do?
+        Build-Depends: base >= 4 && < 5
     else
-        Build-Depends: base < 3
+        -- TODO: What else do we need to do?
+        Build-Depends: base < 4
 
 ----------------------------------------------------------------
 ----------------------------------------------------------- fin.