diff --git a/cucul/font.c b/cucul/font.c
index abf912a..8a16b31 100644
--- a/cucul/font.c
+++ b/cucul/font.c
@@ -180,8 +180,8 @@ cucul_font_t *cucul_load_font(void const *data, unsigned int size)
 
         if(f->glyph_list[i].data_offset >= f->header.data_size
             || f->glyph_list[i].data_offset
-                + f->glyph_list[i].width * f->glyph_list[i].height *
-                  f->header.bpp / 8 >= f->header.data_size)
+                + (f->glyph_list[i].width * f->glyph_list[i].height *
+                   f->header.bpp + 7) / 8 > f->header.data_size)
         {
             free(f->glyph_list);
             free(f->block_list);
@@ -433,4 +433,4 @@ void cucul_render_canvas(cucul_t *qq, cucul_font_t *f,
  * };
  */
 
-#endif
\ No newline at end of file
+#endif