diff --git a/Git/Smoke.hs b/Git/Smoke.hs
--- a/Git/Smoke.hs
+++ b/Git/Smoke.hs
@@ -25,7 +25,7 @@
 import Test.Hspec (Spec, describe, it)
 import Test.Hspec.HUnit ()
 
-sampleCommit :: Repository m => Tree m -> Signature -> m (Commit m)
+sampleCommit :: Repository m => Tree m (TreeKind m) -> Signature -> m (Commit m)
 sampleCommit tr sig =
     createCommit [] (treeRef tr) sig sig "Sample log message.\n" Nothing
 
diff --git a/gitlib-test.cabal b/gitlib-test.cabal
--- a/gitlib-test.cabal
+++ b/gitlib-test.cabal
@@ -1,5 +1,5 @@
 Name:                gitlib-test
-Version:             1.1.0
+Version:             1.2.0
 Synopsis:            Test library for confirming gitlib backend compliance
 License-file:        LICENSE
 License:             MIT