diff --git a/firmware/font.c b/firmware/font.c
index b2ba3baa30..d8f8c59e0d 100644
--- a/firmware/font.c
+++ b/firmware/font.c
@@ -800,7 +800,7 @@ static void glyph_file_write(void* data)
 }
 
 /* save the char codes of the loaded glyphs to a file */
-void glyph_cache_save(int font_id)
+static void glyph_cache_save(int font_id)
 {
     int fd;