diff --git a/enrol/authorize/db/mysql.php b/enrol/authorize/db/mysql.php
index e22f3e48592..05cb576a674 100755
--- a/enrol/authorize/db/mysql.php
+++ b/enrol/authorize/db/mysql.php
@@ -1,15 +1,18 @@
-<?PHP  //$Id$
-
-// MySQL commands for upgrading this enrolment module
-
-function authorize_upgrade($oldversion=0) {
-
-    global $CFG, $THEME, $db;
-
-    $result = true;
-
-    if ($oldversion == 0) {
-        modify_database("$CFG->dirroot/enrol/authorize/db/mysql.sql");
+<?PHP  //$Id$
+
+// MySQL commands for upgrading this enrolment module
+
+function authorize_upgrade($oldversion=0) {
+    global $CFG, $THEME, $db;
+
+    $result = true;
+
+    if (!$tables = $db->MetaColumns($CFG->prefix . 'enrol_authorize')) {
+        $installfirst = true;
+    }
+
+    if ($oldversion == 0 || !empty($installfirst)) {
+        modify_database("$CFG->dirroot/enrol/authorize/db/mysql.sql");
     }
 
     if ($oldversion < 2005071601) {
@@ -27,7 +30,7 @@ function authorize_upgrade($oldversion=0) {
                 handling, please ensure that you have turned loginhttps ON in Admin >> Variables >> Security.");
     }
 
-    return $result;
-}
-
-?>
+    return $result;
+}
+
+?>