diff --git a/database/updates.inc b/database/updates.inc
index e919062929bf..d1fbbddbc735 100644
--- a/database/updates.inc
+++ b/database/updates.inc
@@ -1,19 +1,6 @@
 <?php
 // $Id$
 
-// SCHEMA and SCHEMA_MIN represent the minimum and maximum N modulename_update_N.
-// Update SCHEMA when a new update function is added.  Update SCHEMA_MIN when old
-// update functions are removed.
-function system_version($type) {
-  switch ($type) {
-    case SCHEMA:
-      return 159;
-
-    case SCHEMA_MIN:
-      return 110;
-  }
-}
-
 function system_update_110() {
   $ret = array();
 
diff --git a/includes/install.inc b/includes/install.inc
index 6f8a86f65c06..472cc94077f8 100644
--- a/includes/install.inc
+++ b/includes/install.inc
@@ -27,13 +27,16 @@ foreach (module_list() as $module) {
  *   FALSE.
  */
 function drupal_get_schema_versions($module) {
-  if (!($max = module_invoke($module, 'version', SCHEMA))) {
+  $functions = get_defined_functions();
+  foreach ($functions['user'] as $function) {
+    if (strpos($function, $module .'_update') === 0) {
+      $updates[] = (int) substr($function, strlen($module .'_update_'));
+    }
+  }
+  if (count($updates) == 0) {
     return FALSE;
   }
-  if (!($min = module_invoke($module, 'version', SCHEMA_MIN))) {
-    $min = 1;
-  }
-  return range($min, $max);
+  return $updates;
 }
 
 /**