diff --git a/include/wx/os2/dc.h b/include/wx/os2/dc.h
index 01c4ff4a1c..01d7df0ef1 100644
--- a/include/wx/os2/dc.h
+++ b/include/wx/os2/dc.h
@@ -129,7 +129,7 @@ public:
                                     ,wxCoord*        pY
                                     ,wxCoord*        pDescent = NULL
                                     ,wxCoord*        pExternalLeading = NULL
-                                    ,wxFont*         pTheFont = NULL
+                                    ,const wxFont*   pTheFont = NULL
                                    ) const;
     virtual bool    CanDrawBitmap(void) const;
     virtual bool    CanGetTextExtent(void) const;
diff --git a/src/os2/dc.cpp b/src/os2/dc.cpp
index 11d9169319..d7c5f5139e 100644
--- a/src/os2/dc.cpp
+++ b/src/os2/dc.cpp
@@ -2151,7 +2151,7 @@ void wxDC::DoGetTextExtent(
 , wxCoord*                          pvY
 , wxCoord*                          pvDescent
 , wxCoord*                          pvExternalLeading
-, wxFont*                           pTheFont
+, const wxFont*                     pTheFont
 ) const
 {
     POINTL                          avPoint[TXTBOX_COUNT];