diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectCheckerTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectCheckerTest.java
index 3f58b7501..9fc7fca98 100644
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectCheckerTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/ObjectCheckerTest.java
@@ -1493,8 +1493,8 @@ public class ObjectCheckerTest {
 		}
 
 		StringBuilder b = new StringBuilder();
-		entry(b, "100644 \u00C1");
-		entry(b, "100644 \u004a\u0301");
+		entry(b, "100644 \u0065\u0301");
+		entry(b, "100644 \u00e9");
 		byte[] data = b.toString().getBytes("UTF-8");
 		try {
 			checker.setSafeForMacOS(true);
@@ -1505,6 +1505,15 @@ public class ObjectCheckerTest {
 		}
 	}
 
+	@Test
+	public void testInvalidTreeDuplicateNames8()
+			throws UnsupportedEncodingException, CorruptObjectException {
+		StringBuilder b = new StringBuilder();
+		entry(b, "100644 A");
+		checker.setSafeForMacOS(true);
+		checker.checkTree(b.toString().getBytes("UTF-8"));
+	}
+
 	@Test
 	public void testRejectNulInPathSegment() {
 		try {
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java
index 1b135a924..d8a70c104 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/ObjectChecker.java
@@ -382,7 +382,7 @@ public class ObjectChecker {
 				throw new CorruptObjectException("truncated in name");
 			checkPathSegment2(raw, thisNameB, ptr);
 			if (normalized != null) {
-				if (normalized.add(normalize(raw, thisNameB, ptr)))
+				if (!normalized.add(normalize(raw, thisNameB, ptr)))
 					throw new CorruptObjectException("duplicate entry names");
 			} else if (duplicateName(raw, thisNameB, ptr))
 				throw new CorruptObjectException("duplicate entry names");