diff --git a/admin/cli/install.php b/admin/cli/install.php
index 38aa06e87d2..858571fd03d 100644
--- a/admin/cli/install.php
+++ b/admin/cli/install.php
@@ -164,6 +164,7 @@ require_once($CFG->libdir.'/moodlelib.php');
 require_once($CFG->libdir.'/deprecatedlib.php');
 require_once($CFG->libdir.'/adminlib.php');
 require_once($CFG->libdir.'/componentlib.class.php');
+require_once($CFG->dirroot.'/cache/lib.php');
 
 require($CFG->dirroot.'/version.php');
 $CFG->target_release = $release;
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 5c384c319dd..960442d53e5 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -7030,9 +7030,6 @@ class core_string_manager implements string_manager {
      */
     public function get_revision() {
         global $CFG;
-        if (!$this->usediskcache) {
-            return -1;
-        }
         if (isset($CFG->langrev)) {
             return (int)$CFG->langrev;
         } else {