diff --git a/ChangeLog b/ChangeLog
index 80f5ef568..0c701a342 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2010-12-26  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	Handling of files of unknown size is currently limited. They can't be
+	used e.g. for initrd or modules. Moreover gzip handling of not
+	easily seekable files is buggy. Disable unknown file size for now. May
+	be inefficient but works.
+
+	* grub-core/io/gzio.c (test_header): Always retrieve the file size.
+	* grub-core/io/xzio.c (grub_xzio_open): Likewise.
+
 2010-12-25  Mirko Parthey <mirko.parthey@informatik.tu-chemnitz.de>
 
 	* grub-core/boot/i386/pc/boot.S: Fix %es:%bx pointing to nowhere on
diff --git a/grub-core/io/gzio.c b/grub-core/io/gzio.c
index 43b67c373..f563d7b92 100644
--- a/grub-core/io/gzio.c
+++ b/grub-core/io/gzio.c
@@ -212,19 +212,18 @@ test_header (grub_file_t file)
 
   gzio->data_offset = grub_file_tell (gzio->file);
 
-  grub_file_seek (gzio->file, grub_file_size (gzio->file) - 4);
-
-  if (grub_file_seekable (gzio->file))
-    {
-      if (grub_file_read (gzio->file, &orig_len, 4) != 4)
-	{
-	  grub_error (GRUB_ERR_BAD_FILE_TYPE, "unsupported gzip format");
-	  return 0;
-	}
-    }
-  /* FIXME: this does not handle files whose original size is over 4GB.
-     But how can we know the real original size?  */
-  file->size = grub_le_to_cpu32 (orig_len);
+  /* FIXME: don't do this on not easily seekable files.  */
+  {
+    grub_file_seek (gzio->file, grub_file_size (gzio->file) - 4);
+    if (grub_file_read (gzio->file, &orig_len, 4) != 4)
+      {
+	grub_error (GRUB_ERR_BAD_FILE_TYPE, "unsupported gzip format");
+	return 0;
+      }
+    /* FIXME: this does not handle files whose original size is over 4GB.
+       But how can we know the real original size?  */
+    file->size = grub_le_to_cpu32 (orig_len);
+  }
 
   initialize_tables (file);
 
diff --git a/grub-core/io/xzio.c b/grub-core/io/xzio.c
index 1a22bdc70..37be1790f 100644
--- a/grub-core/io/xzio.c
+++ b/grub-core/io/xzio.c
@@ -222,7 +222,8 @@ grub_xzio_open (grub_file_t io)
   xzio->buf.out_pos = 0;
   xzio->buf.out_size = XZBUFSIZ;
 
-  if (!test_header (file) || !(grub_file_seekable (io) && test_footer (file)))
+  /* FIXME: don't test footer on not easily seekable files.  */
+  if (!test_header (file) || !test_footer (file))
     {
       grub_errno = GRUB_ERR_NONE;
       grub_file_seek (io, 0);