diff --git a/include/wx/propgrid/propgrid.h b/include/wx/propgrid/propgrid.h
index 4be014818b..a38df7c7e4 100644
--- a/include/wx/propgrid/propgrid.h
+++ b/include/wx/propgrid/propgrid.h
@@ -1313,7 +1313,7 @@ public:
 
     // Returns true if given event is from first of an array of buttons
     // (as can be in case when wxPGMultiButton is used).
-    bool IsMainButtonEvent( const wxEvent& event )
+    bool IsMainButtonEvent( const wxEvent& event ) const
     {
         return (event.GetEventType() == wxEVT_BUTTON)
                     && (m_wndSecId == event.GetId());
@@ -1839,7 +1839,7 @@ protected:
         return KeyEventToActions(event, NULL);
     }
 
-    void ImprovedClientToScreen( int* px, int* py );
+    void ImprovedClientToScreen( int* px, int* py ) const;
 
     // Called by focus event handlers. newFocused is the window that becomes
     // focused.
diff --git a/src/propgrid/propgrid.cpp b/src/propgrid/propgrid.cpp
index e74fee0b22..2b5dcd2889 100644
--- a/src/propgrid/propgrid.cpp
+++ b/src/propgrid/propgrid.cpp
@@ -3822,7 +3822,7 @@ wxSize wxPropertyGrid::GetImageSize( wxPGProperty* p, int item ) const
 // -----------------------------------------------------------------------
 
 // takes scrolling into account
-void wxPropertyGrid::ImprovedClientToScreen( int* px, int* py )
+void wxPropertyGrid::ImprovedClientToScreen( int* px, int* py ) const
 {
     wxASSERT(px && py);
     CalcScrolledPosition(*px, *py, px, py);