diff --git a/src/mac/app.cpp b/src/mac/app.cpp
index 78cf0b25da..c79d9536fc 100644
--- a/src/mac/app.cpp
+++ b/src/mac/app.cpp
@@ -678,6 +678,7 @@ void wxApp::CleanUp()
         delete wxWinMacControlList ;
     }
     delete wxPendingEvents;
+    wxPendingEvents = NULL;
 
 #if wxUSE_THREADS
     delete wxPendingEventsLocker;
diff --git a/src/mac/carbon/app.cpp b/src/mac/carbon/app.cpp
index 78cf0b25da..c79d9536fc 100644
--- a/src/mac/carbon/app.cpp
+++ b/src/mac/carbon/app.cpp
@@ -678,6 +678,7 @@ void wxApp::CleanUp()
         delete wxWinMacControlList ;
     }
     delete wxPendingEvents;
+    wxPendingEvents = NULL;
 
 #if wxUSE_THREADS
     delete wxPendingEventsLocker;