diff --git a/src/msw/region.cpp b/src/msw/region.cpp
index ce34b66919..4da2054b10 100644
--- a/src/msw/region.cpp
+++ b/src/msw/region.cpp
@@ -354,7 +354,7 @@ WXHRGN wxRegion::GetHRGN() const
 void wxRegionIterator::Init()
 {
     m_current =
-    m_numRects = NULL;
+    m_numRects = 0;
 
     m_rects = NULL;
 }