diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/BitmapIndexImpl.java b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/BitmapIndexImpl.java
index a8c8aaebc..47adb914f 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/BitmapIndexImpl.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/file/BitmapIndexImpl.java
@@ -318,7 +318,8 @@ public class BitmapIndexImpl implements BitmapIndex {
 			return true;
 		}
 
-		BitmapIndexImpl getBitmapIndex() {
+		@Override
+		public BitmapIndexImpl getBitmapIndex() {
 			return BitmapIndexImpl.this;
 		}
 	}
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/BitmapIndex.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/BitmapIndex.java
index a4b4b6ef2..037d3fd2a 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/BitmapIndex.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/BitmapIndex.java
@@ -204,5 +204,12 @@ public interface BitmapIndex {
 
 		/** @return the number of elements in the bitmap. */
 		int cardinality();
+
+		/**
+		 * The BitmapIndex for this BitmapBuilder.
+		 *
+		 * @since 4.2
+		 */
+		BitmapIndex getBitmapIndex();
 	}
 }