diff --git a/include/efi_loader.h b/include/efi_loader.h
index 2bcca3d..5fe17b0 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -252,7 +252,8 @@ extern void *efi_bounce_buffer;
 
 
 struct efi_device_path *efi_dp_next(const struct efi_device_path *dp);
-int efi_dp_match(struct efi_device_path *a, struct efi_device_path *b);
+int efi_dp_match(const struct efi_device_path *a,
+		 const struct efi_device_path *b);
 struct efi_object *efi_dp_find_obj(struct efi_device_path *dp,
 				   struct efi_device_path **rem);
 unsigned efi_dp_size(const struct efi_device_path *dp);
diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c
index f6e368e..0248771 100644
--- a/lib/efi_loader/efi_device_path.c
+++ b/lib/efi_loader/efi_device_path.c
@@ -68,7 +68,8 @@ struct efi_device_path *efi_dp_next(const struct efi_device_path *dp)
  * representing a device with one representing a file on the device, or
  * a device with a parent device.
  */
-int efi_dp_match(struct efi_device_path *a, struct efi_device_path *b)
+int efi_dp_match(const struct efi_device_path *a,
+		 const struct efi_device_path *b)
 {
 	while (1) {
 		int ret;