diff --git a/ssd1306.c b/ssd1306.c
--- a/ssd1306.c
+++ b/ssd1306.c
@@ -62,7 +62,7 @@ void ssd1306_Init(void)
 
 
 // Times New Roman font
-const char fontData[][5] =
+static const char fontData[][5] =
 {                                       // Refer to "Times New Roman" Font Database
                                         //   Basic Characters
     {0x00,0x00,0x00,0x00,0x00},         //   (  0)    - 0x0020 No-Break Space