diff --git a/debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/model/CThread.java b/debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/model/CThread.java
index d7598b3afd8..5dc5d47a30e 100644
--- a/debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/model/CThread.java
+++ b/debug/org.eclipse.cdt.debug.core/src/org/eclipse/cdt/debug/internal/core/model/CThread.java
@@ -326,7 +326,7 @@ public class CThread extends CDebugElement implements ICThread, IRestart, IResum
 	 * <ul>
 	 * </ul>
 	 */
-	public List computeStackFrames() throws DebugException {
+	public synchronized List computeStackFrames() throws DebugException {
 		return computeStackFrames( refreshChildren() );
 	}