diff --git a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/AbstractSemanticHighlightingTest.java b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/AbstractSemanticHighlightingTest.java
index a6c11430998..c9003210b5f 100644
--- a/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/AbstractSemanticHighlightingTest.java
+++ b/core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/AbstractSemanticHighlightingTest.java
@@ -140,8 +140,9 @@ public class AbstractSemanticHighlightingTest extends TestCase {
 		fCurrentHighlighting= semanticHighlighting;
 		enableSemanticHighlighting(semanticHighlighting);
 		EditorTestHelper.forceReconcile(fSourceViewer);
-		assertTrue(EditorTestHelper.joinReconciler(fSourceViewer, 500, 10000, 100));
-		EditorTestHelper.runEventQueue(100);
+		assertTrue(EditorTestHelper.joinReconciler(fSourceViewer, 500, 10000, 500));
+		// give enough time to finish updating the highlighting positions
+		EditorTestHelper.runEventQueue(500);
 	}
 
 	private void enableSemanticHighlighting(String preferenceKey) {