diff --git a/src/common/string.cpp b/src/common/string.cpp
index 0b71a98535..e8bf97b0b4 100644
--- a/src/common/string.cpp
+++ b/src/common/string.cpp
@@ -2128,6 +2128,9 @@ void wxArrayString::Sort(CompareFunction compareFunction)
 
   DoSort();
 
+  // reset it to NULL so that Sort(bool) will work the next time
+  gs_compareFunction = NULL;
+
   END_SORT();
 }