diff --git a/src/gtk1/font.cpp b/src/gtk1/font.cpp
index 2125d30012..a8524ccd8b 100644
--- a/src/gtk1/font.cpp
+++ b/src/gtk1/font.cpp
@@ -215,8 +215,8 @@ void wxFontRefData::InitFromNative()
         }
     }
 
-    switch ( wxToupper(*m_nativeFontInfo.
-                            GetXFontComponent(wxXLFD_SLANT).c_str()) )
+    switch ( wxToupper(m_nativeFontInfo.
+                           GetXFontComponent(wxXLFD_SLANT)[0u]).GetValue() )
     {
         case _T('I'):   // italique
             m_style = wxFONTSTYLE_ITALIC;