diff --git a/lilypond.cabal b/lilypond.cabal
--- a/lilypond.cabal
+++ b/lilypond.cabal
@@ -1,6 +1,6 @@
 
 name:                   lilypond
-version:                1.7
+version:                1.7.1
 author:                 Hans Hoglund
 maintainer:             Hans Hoglund <hans@hanshoglund.se>
 license:                BSD3
@@ -24,12 +24,12 @@
 library
     build-depends:      base                    >= 4 && < 5,
                         semigroups              >= 0.13.0.1 && < 1,
-                        vector-space,
-                        process,
+                        vector-space            >= 0.8.7 && < 0.9,
+                        process                 >= 1.2 && < 1.3,
                         data-default,
                         prettify,
-                        music-pitch-literal     == 1.7,
-                        music-dynamics-literal  == 1.7
+                        music-pitch-literal     == 1.7.1,
+                        music-dynamics-literal  == 1.7.1
     exposed-modules:    Music.Lilypond
                         Music.Lilypond.Pitch
                         Music.Lilypond.Dynamics
diff --git a/src/Music/Lilypond.hs b/src/Music/Lilypond.hs
--- a/src/Music/Lilypond.hs
+++ b/src/Music/Lilypond.hs
@@ -891,6 +891,7 @@
 isDivisibleBy :: (Real a, Real b) => a -> b -> Bool
 isDivisibleBy n = (equalTo 0.0) . snd . properFraction . logBaseR (toRational n) . toRational
 
+equalTo :: Eq a => a -> a -> Bool
 equalTo  = (==)
 
 infixl <=>