diff --git a/ChangeLog b/ChangeLog
index 34de0864b..a932abb07 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2009-12-23  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* video/efi_gop.c (grub_video_gop_get_bitmask): Fix off-by-one in mask
+	size counting.
+
 2009-12-22 Felix Zielcke <fzielcke@z-51.de>
 
 	* util/grub-mkrescue.in (pkglib_DATA): Set to @pkglib_DATA@.
diff --git a/video/efi_gop.c b/video/efi_gop.c
index e2eb2f7ae..9e019ad53 100644
--- a/video/efi_gop.c
+++ b/video/efi_gop.c
@@ -123,7 +123,7 @@ grub_video_gop_get_bitmask (grub_uint32_t mask, unsigned int *mask_size,
     if (!(mask & (1 << i)))
       break;
   *field_pos = i + 1;
-  *mask_size = last_p - *field_pos;
+  *mask_size = last_p - *field_pos + 1;
 }
 
 static grub_err_t