diff --git a/minuitwrp/graphics.c b/minuitwrp/graphics.c
index 9926904..d08e743 100644
--- a/minuitwrp/graphics.c
+++ b/minuitwrp/graphics.c
@@ -300,10 +300,10 @@
     fb->height = vi.yres;
 #ifdef BOARD_HAS_JANKY_BACKBUFFER
     fb->stride = fi.line_length/2;
-    fb->data = (void*) (((unsigned) bits) + vi.yres * fi.line_length);
+    fb->data = (GGLubyte*) (((unsigned long) bits) + vi.yres * fi.line_length);
 #else
     fb->stride = vi.xres_virtual;
-    fb->data = (void*) (((unsigned) bits) + vi.yres * fb->stride * PIXEL_SIZE);
+    fb->data = (GGLubyte*) (((unsigned long) bits) + vi.yres * fb->stride * PIXEL_SIZE);
 #endif
     fb->format = PIXEL_FORMAT;
     if (!has_overlay) {