diff --git a/Tests/test-filediff.hs b/Tests/test-filediff.hs
--- a/Tests/test-filediff.hs
+++ b/Tests/test-filediff.hs
@@ -616,8 +616,18 @@
     F.numAddedLines diff @?= 1 + 3
     F.numDeletedLines diff @?= 1 + 2
 
--- tests
+testSameListConcatenated :: Assertion
+testSameListConcatenated = do
+    let diff = F.diffLists "abc" "abcabc"
 
+    diff @?= F.ListDiff {F.dels = [], F.adds = [(3,'a'),(4,'b'),(5,'c')]}
+
+testSameListConcatenatedWithIntermediate :: Assertion
+testSameListConcatenatedWithIntermediate = do
+    let diff = F.diffLists "abc" "abc*abc"
+
+    diff @?= F.ListDiff {F.dels = [], F.adds = [(3, '*'), (4,'a'),(5,'b'),(6,'c')]}
+
 tests :: TestTree
 tests = testGroup "unit tests"
     [ -- diffing
@@ -735,6 +745,12 @@
     , testCase
         "Testing diff statistics"
         (runTest testDiffStats)
+    , testCase
+        "Testing same list concatenated with itself (case 1)"
+        testSameListConcatenated
+    , testCase
+        "Testing same list concatenated with itself (case 2)"
+        testSameListConcatenatedWithIntermediate
     ]
 
 main :: IO ()
diff --git a/filediff.cabal b/filediff.cabal
--- a/filediff.cabal
+++ b/filediff.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                filediff
-version:             1.0.0.3
+version:             1.0.0.4
 synopsis:            Diffing and patching module
 description:         `filediff` is a Haskell library for creating diffs, and applying diffs to files and directories.
 homepage:            https://github.com/bgwines/filediff
diff --git a/src/Filediff.hs b/src/Filediff.hs
--- a/src/Filediff.hs
+++ b/src/Filediff.hs
@@ -273,8 +273,12 @@
         commonPrefix :: [a]
         commonPrefix = getCommonPrefix xs ys
 
+        -- drop (length commonPrefix) to prevent the "abc" vs. "abc*abc" case
         commonSuffix :: [a]
-        commonSuffix = reverse (getCommonPrefix (reverse xs) (reverse ys))
+        commonSuffix = reverse
+            (getCommonPrefix
+                (reverse (drop (length commonPrefix) xs))
+                (reverse (drop (length commonPrefix) ys)))
 
         getCommonPrefix :: [a] -> [a] -> [a]
         getCommonPrefix as bs = map fst . takeWhile (uncurry (==)) $ zip as bs