diff --git a/Sound/SC3/UGen/Type.hs b/Sound/SC3/UGen/Type.hs
--- a/Sound/SC3/UGen/Type.hs
+++ b/Sound/SC3/UGen/Type.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 --  | Unit Generator ('UGen'), and associated types and instances.
 module Sound.SC3.UGen.Type where
 
@@ -466,7 +468,9 @@
     bit = error "UGen.bit"
     testBit = error "UGen.testBit"
     popCount = error "UGen.popCount"
+#if MIN_VERSION_base(4,7,0)
     bitSizeMaybe = error "UGen.bitSizeMaybe"
+#endif
     isSigned _ = True
 
 {-
diff --git a/hsc3.cabal b/hsc3.cabal
--- a/hsc3.cabal
+++ b/hsc3.cabal
@@ -1,5 +1,5 @@
 Name:              hsc3
-Version:           0.15
+Version:           0.15.1
 Synopsis:          Haskell SuperCollider
 Description:       Haskell client for the SuperCollider synthesis server,
                    <http://audiosynth.com/>.