diff --git a/uisimulator/common/font-player.c b/uisimulator/common/font-player.c
index 0d2d5236cb..f08a98348f 100644
--- a/uisimulator/common/font-player.c
+++ b/uisimulator/common/font-player.c
@@ -539,7 +539,7 @@ static unsigned char font_player_oldlcd[256][7] = {
 
 unsigned char (*font_player)[256][7] = &font_player_newlcd;
 
-void font_init()
+void font_init(void)
 {
     if (is_new_player())
         font_player = &font_player_newlcd;
diff --git a/uisimulator/common/font-player.h b/uisimulator/common/font-player.h
index 8ddf083ca2..bfa88d7321 100644
--- a/uisimulator/common/font-player.h
+++ b/uisimulator/common/font-player.h
@@ -17,7 +17,11 @@
  *
  ****************************************************************************/
 
+#ifndef __FONT_PLAYER_H__
+#define __FONT_PLAYER_H__
+
 extern unsigned char (*font_player)[256][7];
 
-void font_init();
+void font_init(void);
 
+#endif /* __FONT_PLAYER_H__ */