diff --git a/src/Foreign/Storable/Tuple.hs b/src/Foreign/Storable/Tuple.hs
--- a/src/Foreign/Storable/Tuple.hs
+++ b/src/Foreign/Storable/Tuple.hs
@@ -3,18 +3,13 @@
 -}
 module Foreign.Storable.Tuple where
 
+import Foreign.Storable.Unit ()
 import Foreign.Storable (Storable (..), )
 import qualified Foreign.Storable.Record as Store
 import Control.Applicative (liftA2, liftA3, pure, (<*>), )
 
 import Data.Tuple.HT (fst3, snd3, thd3, )
 
-
-instance Storable () where
-   sizeOf    _ = 0
-   alignment _ = 1
-   peek      _ = return ()
-   poke    _ _ = return ()
 
 instance (Storable a, Storable b) => Storable (a,b) where
    sizeOf    = Store.sizeOf storePair
diff --git a/storable-tuple.cabal b/storable-tuple.cabal
--- a/storable-tuple.cabal
+++ b/storable-tuple.cabal
@@ -1,5 +1,5 @@
 Name:         storable-tuple
-Version:      0.0.2
+Version:      0.0.3
 Category:     Data, Foreign
 Synopsis:     Storable instance for pairs and triples
 Description:
@@ -18,6 +18,9 @@
 Build-Type:          Simple
 Tested-With:         GHC==6.8.2
 Cabal-Version:       >=1.6
+Extra-Source-Files:
+  unit/instance/Foreign/Storable/Unit.hs
+  unit/no-instance/Foreign/Storable/Unit.hs
 
 Source-Repository head
   Type:     darcs
@@ -26,25 +29,34 @@
 Source-Repository this
   Type:     darcs
   Location: http://code.haskell.org/~thielema/storable-tuple/
-  Tag:      0.0.2
+  Tag:      0.0.3
 
 Flag splitBase
-  description: Choose the new smaller, split-up base package.
+  Description: Choose the new smaller, split-up base package.
 
+Flag instanceUnit
+  Description: Custom instance Storable ()
+
 Library
   Build-Depends:
     storable-record >=0.0.1 && <0.1,
     utility-ht >=0.0.1 && <0.1
   If flag(splitBase)
-    Build-Depends:
-      base >= 3 && <5
+    If flag(instanceUnit)
+      Build-Depends: base >=3 && <4.9
+      Hs-Source-Dirs: unit/instance
+    Else
+      Build-Depends: base >=4.9 && <5
+      Hs-Source-Dirs: unit/no-instance
   Else
     Build-Depends:
       special-functors >= 1.0 && <1.1,
       base >= 1.0 && < 2
 
-  GHC-Options:         -Wall
+  GHC-Options:         -Wall -fno-warn-orphans
   Hs-Source-Dirs:      src
 
   Exposed-Modules:
     Foreign.Storable.Tuple
+  Other-Modules:
+    Foreign.Storable.Unit
diff --git a/unit/instance/Foreign/Storable/Unit.hs b/unit/instance/Foreign/Storable/Unit.hs
new file mode 100644
--- /dev/null
+++ b/unit/instance/Foreign/Storable/Unit.hs
@@ -0,0 +1,10 @@
+module Foreign.Storable.Unit where
+
+import Foreign.Storable (Storable (..), )
+
+
+instance Storable () where
+   sizeOf    _ = 0
+   alignment _ = 1
+   peek      _ = return ()
+   poke    _ _ = return ()
diff --git a/unit/no-instance/Foreign/Storable/Unit.hs b/unit/no-instance/Foreign/Storable/Unit.hs
new file mode 100644
--- /dev/null
+++ b/unit/no-instance/Foreign/Storable/Unit.hs
@@ -0,0 +1,3 @@
+module Foreign.Storable.Unit where
+
+import Foreign.Storable ()