diff --git a/lv_draw/lv_draw.c b/lv_draw/lv_draw.c
index 09d24e733..913e968ca 100644
--- a/lv_draw/lv_draw.c
+++ b/lv_draw/lv_draw.c
@@ -34,17 +34,17 @@
  **********************/
 
 #if LV_VDB_SIZE != 0
-void (*px_fp)(lv_coord_t x, lv_coord_t y, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) = lv_vpx;
-void (*fill_fp)(const lv_area_t * coords, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) =  lv_vfill;
-void (*letter_fp)(const lv_point_t * pos_p, const lv_area_t * mask, const lv_font_t * font_p, uint32_t letter, lv_color_t color, lv_opa_t opa) = lv_vletter;
-void (*map_fp)(const lv_area_t * cords_p, const lv_area_t * mask_p,
+const void (*px_fp)(lv_coord_t x, lv_coord_t y, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) = lv_vpx;
+const void (*fill_fp)(const lv_area_t * coords, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) =  lv_vfill;
+const void (*letter_fp)(const lv_point_t * pos_p, const lv_area_t * mask, const lv_font_t * font_p, uint32_t letter, lv_color_t color, lv_opa_t opa) = lv_vletter;
+const void (*map_fp)(const lv_area_t * cords_p, const lv_area_t * mask_p,
                const uint8_t * map_p, lv_opa_t opa, bool chroma_key, bool alpha_byte,
                lv_color_t recolor, lv_opa_t recolor_opa) = lv_vmap;
 #else
-void (*px_fp)(lv_coord_t x, lv_coord_t y, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) = lv_rpx;
-void (*fill_fp)(const lv_area_t * coords, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) =  lv_rfill;
-void (*letter_fp)(const lv_point_t * pos_p, const lv_area_t * mask, const lv_font_t * font_p, uint32_t letter, lv_color_t color, lv_opa_t opa) = lv_rletter;
-void (*map_fp)(const lv_area_t * cords_p, const lv_area_t * mask_p,
+const void (*px_fp)(lv_coord_t x, lv_coord_t y, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) = lv_rpx;
+const void (*fill_fp)(const lv_area_t * coords, const lv_area_t * mask, lv_color_t color, lv_opa_t opa) =  lv_rfill;
+const void (*letter_fp)(const lv_point_t * pos_p, const lv_area_t * mask, const lv_font_t * font_p, uint32_t letter, lv_color_t color, lv_opa_t opa) = lv_rletter;
+const void (*map_fp)(const lv_area_t * cords_p, const lv_area_t * mask_p,
                       const uint8_t * map_p, lv_opa_t opa, bool chroma_key, bool alpha_byte,
                       lv_color_t recolor, lv_opa_t recolor_opa) = lv_rmap;
 #endif
diff --git a/lv_draw/lv_draw.h b/lv_draw/lv_draw.h
index 0efe8d54f..04155cea0 100644
--- a/lv_draw/lv_draw.h
+++ b/lv_draw/lv_draw.h
@@ -88,10 +88,10 @@ void lv_draw_aa_hor_seg(lv_coord_t x, lv_coord_t y, lv_coord_t length, const lv_
 /**********************
  *  GLOBAL VARIABLES
  **********************/
-extern void (*px_fp)(lv_coord_t x, lv_coord_t y, const lv_area_t * mask, lv_color_t color, lv_opa_t opa);
-extern void (*fill_fp)(const lv_area_t * coords, const lv_area_t * mask, lv_color_t color, lv_opa_t opa);
-extern void (*letter_fp)(const lv_point_t * pos_p, const lv_area_t * mask, const lv_font_t * font_p, uint32_t letter, lv_color_t color, lv_opa_t opa);
-extern void (*map_fp)(const lv_area_t * cords_p, const lv_area_t * mask_p,
+extern const void (*px_fp)(lv_coord_t x, lv_coord_t y, const lv_area_t * mask, lv_color_t color, lv_opa_t opa);
+extern const void (*fill_fp)(const lv_area_t * coords, const lv_area_t * mask, lv_color_t color, lv_opa_t opa);
+extern const void (*letter_fp)(const lv_point_t * pos_p, const lv_area_t * mask, const lv_font_t * font_p, uint32_t letter, lv_color_t color, lv_opa_t opa);
+extern const void (*map_fp)(const lv_area_t * cords_p, const lv_area_t * mask_p,
                const uint8_t * map_p, lv_opa_t opa, bool chroma_key, bool alpha_byte,
                lv_color_t recolor, lv_opa_t recolor_opa);