diff --git a/src/mac/app.cpp b/src/mac/app.cpp
index bedbae9605..ebc798b4fd 100644
--- a/src/mac/app.cpp
+++ b/src/mac/app.cpp
@@ -651,6 +651,7 @@ 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 bedbae9605..ebc798b4fd 100644
--- a/src/mac/carbon/app.cpp
+++ b/src/mac/carbon/app.cpp
@@ -651,6 +651,7 @@ void wxApp::CleanUp()
         delete wxWinMacControlList ;
     }
     delete wxPendingEvents;
+    wxPendingEvents = NULL;
 
 #if wxUSE_THREADS
     delete wxPendingEventsLocker;