diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/lib/IndexDiff.java b/org.eclipse.jgit/src/org/eclipse/jgit/lib/IndexDiff.java
index 380ca3f86..73bda0858 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/lib/IndexDiff.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/lib/IndexDiff.java
@@ -82,7 +82,7 @@
  */
 public class IndexDiff {
 
-	private final class ProgressReportingFilter extends TreeFilter {
+	private static final class ProgressReportingFilter extends TreeFilter {
 
 		private final ProgressMonitor monitor;