diff --git a/include/wx/generic/grid.h b/include/wx/generic/grid.h
index 0817377738..9c1f0083ee 100644
--- a/include/wx/generic/grid.h
+++ b/include/wx/generic/grid.h
@@ -1405,6 +1405,8 @@ public:
     {
         m_extraWidth = extraWidth;
         m_extraHeight = extraHeight;
+
+        CalcDimensions();
     }
 
     // Accessors for component windows