Index: pc.c
===================================================================
--- pc.c        (revision 1861)
+++ pc.c        (working copy)
@@ -19,11 +19,17 @@

 #include <grub/partition.h>
 #include <grub/pc_partition.h>
+#include <grub/gpt_partition.h>
 #include <grub/disk.h>
 #include <grub/mm.h>
 #include <grub/misc.h>
 #include <grub/dl.h>

+static grub_uint8_t grub_gpt_magic[8] =
+  {
+    0x45, 0x46, 0x49, 0x20, 0x50, 0x41, 0x52, 0x54
+  };
+
 static struct grub_partition_map grub_pc_partition_map;

 #ifndef GRUB_UTIL
@@ -111,6 +117,13 @@
   pcdata.dos_part = -1;
   p.data = &pcdata;
   p.partmap = &grub_pc_partition_map;
+
+  /* Read the GPT header.  */
+  if (grub_disk_read (&raw, 1, 0, sizeof (gpt), (char *) &gpt))
+    return grub_errno;
+
+  if (!grub_memcmp (gpt.magic, grub_gpt_magic, sizeof (grub_gpt_magic)))
+    return grub_error (GRUB_ERR_BAD_PART_TABLE, "valid GPT header");

   while (1)
     {
Index: gpt.c
===================================================================
--- gpt.c       (revision 1861)
+++ gpt.c       (working copy)
@@ -58,18 +58,6 @@
   raw = *disk;
   raw.partition = 0;

-  /* Read the protective MBR.  */
-  if (grub_disk_read (&raw, 0, 0, sizeof (mbr), (char *) &mbr))
-    return grub_errno;
-
-  /* Check if it is valid.  */
-  if (mbr.signature != grub_cpu_to_le16 (GRUB_PC_PARTITION_SIGNATURE))
-    return grub_error (GRUB_ERR_BAD_PART_TABLE, "no signature");
-
-  /* Make sure the MBR is a protective MBR and not a normal MBR.  */
-  if (mbr.entries[0].type != GRUB_PC_PARTITION_TYPE_GPT_DISK)
-    return grub_error (GRUB_ERR_BAD_PART_TABLE, "no GPT partition map found");
-
   /* Read the GPT header.  */
   if (grub_disk_read (&raw, 1, 0, sizeof (gpt), (char *) &gpt))
     return grub_errno;