diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java
index e7e2b0034..965ccb098 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/Repository.java
@@ -112,6 +112,12 @@ import org.slf4j.LoggerFactory;
  * <li>{@code FileRepository} is thread-safe.
  * <li>{@code DfsRepository} thread-safety is determined by its subclass.
  * </ul>
+ * <p>
+ * <i>Note to implementors:</i> Make sure to override
+ * {@link #notifyIndexChanged(boolean)} or {@link #notifyIndexChanged()}, or
+ * else both will throw {@code StackOverflowException}. In the next JGit minor
+ * release, {@link #notifyIndexChanged(boolean)} will be abstract and {@link
+ * #notifyIndexChanged()} will be final.
  */
 public abstract class Repository implements AutoCloseable {
 	private static final Logger LOG = LoggerFactory.getLogger(Repository.class);
@@ -1567,15 +1573,31 @@ public abstract class Repository implements AutoCloseable {
 	 */
 	public abstract void scanForRepoChanges() throws IOException;
 
+	/**
+	 * Backward compatibility synonym for {@code notifyIndexChanged(true)}.
+	 *
+	 * @deprecated replaced by {@link #notifyIndexChanged(boolean)}
+	 */
+	@Deprecated
+	public void notifyIndexChanged() {
+		notifyIndexChanged(true);
+	}
+
 	/**
 	 * Notify that the index changed by firing an IndexChangedEvent.
+	 * <p>
+	 * The default implementation calls {@link #notifyIndexChanged()} for
+	 * backward compatibility but will no longer do so in the next JGit minor
+	 * release. Implementors should override this method directly instead.
 	 *
 	 * @param internal
 	 *                     {@code true} if the index was changed by the same
 	 *                     JGit process
 	 * @since 5.0
 	 */
-	public abstract void notifyIndexChanged(boolean internal);
+	public void notifyIndexChanged(boolean internal) {
+		notifyIndexChanged();
+	}
 
 	/**
 	 * Get a shortened more user friendly ref name