diff --git a/util/misc.c b/util/misc.c
index b0e023ecd..b8ec69108 100644
--- a/util/misc.c
+++ b/util/misc.c
@@ -89,6 +89,8 @@ grub_util_get_image_size (const char *path)
   fseeko (f, 0, SEEK_END);
   
   sz = ftello (f);
+  if (sz < 0)
+    grub_util_error (_("cannot open `%s': %s"), path, strerror (errno));
   if (sz != (size_t) sz)
     grub_util_error (_("file `%s' is too big"), path);
   ret = (size_t) sz;