diff --git a/commands/sql/sql.drush.inc b/commands/sql/sql.drush.inc
index 269ce5e..c0d6827 100644
--- a/commands/sql/sql.drush.inc
+++ b/commands/sql/sql.drush.inc
@@ -1110,15 +1110,15 @@ function drush_sql_dump_file(&$site_record) {
         else {
           $dump_dir = trim($result['output']);
         }
-        $dump_file = $dump_dir . '/' . $filename_pattern . '.sql';
+        $dump_file = drush_tempnam($filename_pattern, $dump_dir, 'sql';
       }
       else {
-        $dump_file = drush_tempnam($filename_pattern . '.sql.');
+        $dump_file = drush_tempnam($filename_pattern, NULL, 'sql.');
       }
       $site_record['dump-is-temp'] = TRUE;
     }
     else {
-      $dump_file = $dump_dir . '/' . $filename_pattern . '.sql';
+      $dump_file = drush_tempnam($filename_pattern, $dump_dir, 'sql');
     }
   }