diff --git a/language-dot.cabal b/language-dot.cabal
--- a/language-dot.cabal
+++ b/language-dot.cabal
@@ -1,5 +1,5 @@
 name:         language-dot
-version:      0.0.5
+version:      0.0.6
 category:     Language
 synopsis:     A library for the analysis and creation of Graphviz DOT files
 description:  A library for the analysis and creation of Graphviz DOT files.
@@ -31,7 +31,7 @@
 
   build-depends:
     base   == 4.*,
-    mtl    == 1.*,
+    mtl    == 1.* || == 2.*,
     parsec == 3.*,
     pretty == 1.*