diff --git a/wxPython/contrib/gizmos/treelistctrl.cpp b/wxPython/contrib/gizmos/treelistctrl.cpp
index dd28097b8f..7136af2362 100644
--- a/wxPython/contrib/gizmos/treelistctrl.cpp
+++ b/wxPython/contrib/gizmos/treelistctrl.cpp
@@ -854,7 +854,7 @@ private:
     wxArrayShort m_col_images; // images for the various columns (!= main)
 
     wxCoord             m_x;            // (virtual) offset from top
-    short               m_y;            // (virtual) offset from left
+    wxCoord             m_y;            // (virtual) offset from left
     short               m_width;        // width of this item
     unsigned char       m_height;       // height of this item