diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
index ceadb420996..d27aebb3716 100644
--- a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
+++ b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
@@ -208,7 +208,9 @@ public class TestBackwardsCompatibility extends LuceneTestCase {
 
   final static String[] oldNames = {
       "5.0.0-cfs",
-      "5.0.0-nocfs"
+      "5.0.0-nocfs",
+      "5.1.0-cfs",
+      "5.1.0-nocfs"
   };
   
   final String[] unsupportedNames = {
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/index.5.1.0-cfs.zip b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.5.1.0-cfs.zip
new file mode 100644
index 00000000000..569b3532fc3
Binary files /dev/null and b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.5.1.0-cfs.zip differ
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/index.5.1.0-nocfs.zip b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.5.1.0-nocfs.zip
new file mode 100644
index 00000000000..21422e3b6e4
Binary files /dev/null and b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.5.1.0-nocfs.zip differ