diff --git a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java
index 83c2f2c..6f154c6 100644
--- a/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java
+++ b/dsf/org.eclipse.cdt.dsf.ui/src/org/eclipse/cdt/dsf/debug/internal/ui/disassembly/DisassemblyPart.java
@@ -1495,7 +1495,8 @@
 	 */
 	@Override
 	public void viewportChanged(int verticalOffset) {
-		if (fDebugSessionId != null && fGotoAddressPending == PC_UNKNOWN && fScrollPos == null && !fUpdatePending && !fRefreshViewPending) {
+		if (fDebugSessionId != null && fGotoAddressPending == PC_UNKNOWN && fScrollPos == null && !fUpdatePending && !fRefreshViewPending 
+				&& fFocusAddress != PC_UNKNOWN) {
 			fUpdatePending = true;
             final int updateCount = fUpdateCount;
             invokeLater(new Runnable() {