diff --git a/grub-core/lib/reed_solomon.c b/grub-core/lib/reed_solomon.c
index 3d8bb9e1f..0257342d0 100644
--- a/grub-core/lib/reed_solomon.c
+++ b/grub-core/lib/reed_solomon.c
@@ -25,6 +25,10 @@
 #define grub_memcpy memcpy
 #endif
 
+#ifndef STANDALONE
+#include <assert.h>
+#endif
+
 #ifndef STANDALONE
 #ifdef TEST
 typedef unsigned int grub_size_t;
@@ -456,6 +460,10 @@ grub_reed_solomon_add_redundancy (void *buffer, grub_size_t data_size,
   grub_size_t rs = redundancy;
   gf_single_t *ptr = buffer;
   gf_single_t *rptr = ptr + s;
+  void *tmp;
+
+  tmp = xmalloc (data_size);
+  grub_memcpy (tmp, buffer, data_size);
 
   /* Nothing to do.  */
   if (!rs)
@@ -481,6 +489,9 @@ grub_reed_solomon_add_redundancy (void *buffer, grub_size_t data_size,
       s -= cs;
       rs -= crs;
     }
+
+  assert (grub_memcmp (tmp, buffer, data_size) == 0);
+  free (tmp);
 }
 #endif
 
diff --git a/util/grub-setup.c b/util/grub-setup.c
index d3b3b7520..8965143c5 100644
--- a/util/grub-setup.c
+++ b/util/grub-setup.c
@@ -448,10 +448,14 @@ setup (const char *dir,
 			+ GRUB_KERNEL_I386_PC_REED_SOLOMON_REDUNDANCY)
       = grub_host_to_target32 (nsec * GRUB_DISK_SECTOR_SIZE - core_size);
 
+    void *tmp = xmalloc (core_size);
+    grub_memcpy (tmp, core_img, core_size);
     grub_reed_solomon_add_redundancy (core_img + GRUB_KERNEL_I386_PC_NO_REED_SOLOMON_PART + GRUB_DISK_SECTOR_SIZE,
 				      core_size - GRUB_KERNEL_I386_PC_NO_REED_SOLOMON_PART - GRUB_DISK_SECTOR_SIZE,
 				      nsec * GRUB_DISK_SECTOR_SIZE
 				      - core_size);
+    assert (grub_memcmp (tmp, core_img, core_size) == 0);
+    free (tmp);
 
     /* Make sure that the second blocklist is a terminator.  */
     block = first_block - 1;