diff --git a/core/src/test/java/org/elasticsearch/common/bytes/AbstractBytesReferenceTestCase.java b/core/src/test/java/org/elasticsearch/common/bytes/AbstractBytesReferenceTestCase.java
index 76757e76724..f31d7c69325 100644
--- a/core/src/test/java/org/elasticsearch/common/bytes/AbstractBytesReferenceTestCase.java
+++ b/core/src/test/java/org/elasticsearch/common/bytes/AbstractBytesReferenceTestCase.java
@@ -394,7 +394,7 @@ public abstract class AbstractBytesReferenceTestCase extends ESTestCase {
     public void testSliceArrayOffset() throws IOException {
         int length = randomInt(PAGE_SIZE * randomIntBetween(2, 5));
         BytesReference pbr = newBytesReference(length);
-        int sliceOffset = randomIntBetween(0, pbr.length() - 1);
+        int sliceOffset = randomIntBetween(0, pbr.length() - 1); // an offset to the end would be len 0
         int sliceLength = randomIntBetween(pbr.length() - sliceOffset, pbr.length() - sliceOffset);
         BytesReference slice = pbr.slice(sliceOffset, sliceLength);
         if (slice.hasArray()) {