diff --git a/debug/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/signals/SignalsView.java b/debug/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/signals/SignalsView.java
index 03f651c14a1..45b28246db2 100644
--- a/debug/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/signals/SignalsView.java
+++ b/debug/org.eclipse.cdt.debug.ui/src/org/eclipse/cdt/debug/internal/ui/views/signals/SignalsView.java
@@ -178,6 +178,11 @@ public class SignalsView extends AbstractDebugEventHandlerView
 			}
 		}
 
+		if ( getViewer() == null )
+		{
+			return;
+		}
+
 		Object current = getViewer().getInput();
 		if ( current != null && current.equals( sm ) )
 		{