diff --git a/bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/quickdiff/LastSaveReferenceProvider.java b/bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/quickdiff/LastSaveReferenceProvider.java
index 5761592b77b..cf1fa874601 100644
--- a/bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/quickdiff/LastSaveReferenceProvider.java
+++ b/bundles/org.eclipse.ui.editors/src/org/eclipse/ui/internal/editors/quickdiff/LastSaveReferenceProvider.java
@@ -59,6 +59,11 @@
  */
 public class LastSaveReferenceProvider implements IQuickDiffReferenceProvider, IElementStateListener {
 
+	/**
+	 * Family for jobs started by {@link LastSaveReferenceProvider}.
+	 */
+	public static final Object JOB_FAMILY = new Object();
+
 	/** <code>true</code> if the document has been read. */
 	private boolean fDocumentRead= false;
 	/**
@@ -117,6 +122,11 @@ protected IStatus run(IProgressMonitor monitor) {
 			readDocument(monitor, false);
 			return Status.OK_STATUS;
 		}
+
+		@Override
+		public boolean belongsTo(Object family) {
+			return family == JOB_FAMILY;
+		}
 	}
 
 	@Override