diff --git a/graph-wrapper.cabal b/graph-wrapper.cabal
--- a/graph-wrapper.cabal
+++ b/graph-wrapper.cabal
@@ -1,7 +1,7 @@
 Cabal-Version:      >= 1.8
 Build-Type:         Simple
 Name:               graph-wrapper
-Version:            0.2.5.1
+Version:            0.2.5.2
 Maintainer:         Max Bolingbroke <batterseapower@hotmail.com>, Sönke Hahn <soenkehahn@gmail.com>
 Homepage:           https://github.com/soenkehahn/graph-wrapper
 License:            BSD3
@@ -25,7 +25,7 @@
     Build-Depends:
         base >= 3.0 && < 5.0,
         array >= 0.3 && < 0.6,
-        containers >= 0.3 && < 0.6
+        containers >= 0.3 && < 0.7
 
 test-suite spec
     type:
@@ -41,3 +41,7 @@
         deepseq,
         hspec,
         QuickCheck
+    other-modules:
+      Data.Graph.Wrapper
+      Data.Graph.Wrapper.Internal
+      Data.Graph.WrapperSpec
diff --git a/test/Data/Graph/WrapperSpec.hs b/test/Data/Graph/WrapperSpec.hs
new file mode 100644
--- /dev/null
+++ b/test/Data/Graph/WrapperSpec.hs
@@ -0,0 +1,23 @@
+
+module Data.Graph.WrapperSpec where
+
+
+import           Control.DeepSeq
+import           Test.Hspec
+import           Test.QuickCheck
+
+import           Data.Graph.Wrapper
+
+
+spec :: Spec
+spec = do
+  describe "fromListLenient" $ do
+    it "does not crash" $ do
+      property $ \ list ->
+        deepseq (toList (fromListLenient list :: Graph Integer ())) True
+
+  describe "reachableVertices" $ do
+    context "when the vertex is not in the given graph" $ do
+      it "returns the empty list" $ do
+        reachableVertices (fromList [] :: Graph Integer ()) 0
+          `shouldBe` []