diff --git a/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java b/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java
index c31956a4aa3..30eae21148a 100644
--- a/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java
+++ b/codan/org.eclipse.cdt.codan.ui.cxx/src/org/eclipse/cdt/codan/internal/ui/cxx/Startup.java
@@ -37,6 +37,8 @@ public class Startup implements IStartup {
 			@Override
 			public void run() {
 				IWorkbenchWindow active = workbench.getActiveWorkbenchWindow();
+				if (active == null)
+					return;  // The workbench is shutting down.
 				final IWorkbenchPage page = active.getActivePage();
 				CodanPartListener partListener = new CodanPartListener();
 				page.addPartListener(partListener);