diff --git a/ChangeLog b/ChangeLog
index 857692351..527e9d17c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2012-09-12  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* include/grub/efi/api.h (grub_efi_runtime_services): Make vendor_guid
+	a const pointer.
+	* grub-core/efiemu/runtime/efiemu.c (efiemu_memcpy): Make from a
+	const pointer.
+	(efiemu_set_variable): Make vendor_guid a const pointer.
+
 2012-09-12  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	Don't require grub-mkconfig_lib to generate manpages for programs.
diff --git a/grub-core/efiemu/runtime/efiemu.c b/grub-core/efiemu/runtime/efiemu.c
index 84b02cb20..d923e409f 100644
--- a/grub-core/efiemu/runtime/efiemu.c
+++ b/grub-core/efiemu/runtime/efiemu.c
@@ -78,7 +78,7 @@ efiemu_get_next_variable_name (grub_efi_uintn_t *variable_name_size,
 
 grub_efi_status_t
 efiemu_set_variable (grub_efi_char16_t *variable_name,
-		     grub_efi_guid_t *vendor_guid,
+		     const grub_efi_guid_t *vendor_guid,
 		     grub_efi_uint32_t attributes,
 		     grub_efi_uintn_t data_size,
 		     void *data);
@@ -131,11 +131,11 @@ extern grub_uint32_t efiemu_time_accuracy;
 
 /* Some standard functions because we need to be standalone */
 static void
-efiemu_memcpy (void *to, void *from, int count)
+efiemu_memcpy (void *to, const void *from, int count)
 {
   int i;
   for (i = 0; i < count; i++)
-    ((grub_uint8_t *) to)[i] = ((grub_uint8_t *) from)[i];
+    ((grub_uint8_t *) to)[i] = ((const grub_uint8_t *) from)[i];
 }
 
 static int
@@ -503,10 +503,10 @@ grub_efi_status_t EFI_FUNC
 
 grub_efi_status_t
 EFI_FUNC (efiemu_set_variable) (grub_efi_char16_t *variable_name,
-				   grub_efi_guid_t *vendor_guid,
-				   grub_efi_uint32_t attributes,
-				   grub_efi_uintn_t data_size,
-				   void *data)
+				const grub_efi_guid_t *vendor_guid,
+				grub_efi_uint32_t attributes,
+				grub_efi_uintn_t data_size,
+				void *data)
 {
   struct efi_variable *efivar;
   grub_uint8_t *ptr;
diff --git a/include/grub/efi/api.h b/include/grub/efi/api.h
index ae6173098..2917d1426 100644
--- a/include/grub/efi/api.h
+++ b/include/grub/efi/api.h
@@ -1208,7 +1208,7 @@ struct grub_efi_runtime_services
 
   grub_efi_status_t
   (*set_variable) (grub_efi_char16_t *variable_name,
-		   grub_efi_guid_t *vendor_guid,
+		   const grub_efi_guid_t *vendor_guid,
 		   grub_efi_uint32_t attributes,
 		   grub_efi_uintn_t data_size,
 		   void *data);