diff --git a/storage/archive/ha_archive.cc b/storage/archive/ha_archive.cc
index 7b943139c24..332afb4d437 100644
--- a/storage/archive/ha_archive.cc
+++ b/storage/archive/ha_archive.cc
@@ -1394,6 +1394,7 @@ int ha_archive::optimize(THD* thd, HA_CHECK_OPT* check_opt)
   char writer_filename[FN_REFLEN];
   DBUG_ENTER("ha_archive::optimize");
 
+  mysql_mutex_lock(&share->mutex);
   init_archive_reader();
 
   // now we close both our writer and our reader for the rename
@@ -1408,7 +1409,10 @@ int ha_archive::optimize(THD* thd, HA_CHECK_OPT* check_opt)
             MY_REPLACE_EXT | MY_UNPACK_FILENAME);
 
   if (!(azopen(&writer, writer_filename, O_CREAT|O_RDWR|O_BINARY)))
+  {
+    mysql_mutex_unlock(&share->mutex);
     DBUG_RETURN(HA_ERR_CRASHED_ON_USAGE); 
+  }
 
   /*
     Transfer the embedded FRM so that the file can be discoverable.
@@ -1494,10 +1498,12 @@ int ha_archive::optimize(THD* thd, HA_CHECK_OPT* check_opt)
   rc= my_rename(writer_filename, share->data_file_name, MYF(0));
 
 
+  mysql_mutex_unlock(&share->mutex);
   DBUG_RETURN(rc);
 error:
   DBUG_PRINT("ha_archive", ("Failed to recover, error was %d", rc));
   azclose(&writer);
+  mysql_mutex_unlock(&share->mutex);
 
   DBUG_RETURN(rc); 
 }