--- a/src/sdl_font.cpp
+++ b/src/sdl_font.cpp
@@ -12,12 +12,12 @@
 {
     const TTF_Font_Ptr fnt( TTF_OpenFontIndex( f.c_str(), size, faceIndex ) );
     if( fnt ) {
-        char *style = TTF_FontFaceStyleName( fnt.get() );
+        const char *style = TTF_FontFaceStyleName( fnt.get() );
         if( style != nullptr ) {
             int faces = TTF_FontFaces( fnt.get() );
             for( int i = faces - 1; i >= 0; i-- ) {
                 const TTF_Font_Ptr tf( TTF_OpenFontIndex( f.c_str(), size, i ) );
-                char *ts = nullptr;
+                const char *ts = nullptr;
                 if( tf ) {
                     if( nullptr != ( ts = TTF_FontFaceStyleName( tf.get() ) ) ) {
                         if( lcequal( ts, style ) && TTF_FontHeight( tf.get() ) <= size ) {