diff --git a/course/lib.php b/course/lib.php
index 0029b8056fe..f844bc564df 100644
--- a/course/lib.php
+++ b/course/lib.php
@@ -4493,6 +4493,7 @@ function include_course_ajax($course, $usedmodules = array(), $enabledmodules =
         'courseid' => $course->id,
         'pagetype' => $PAGE->pagetype,
         'pagelayout' => $PAGE->pagelayout,
+        'subpage' => $PAGE->subpage,
         'regions' => $PAGE->blocks->get_regions(),
     );
     $PAGE->requires->yui_module('moodle-core-blocks', 'M.core_blocks.init_dragdrop', array($params), null, true);
diff --git a/lib/ajax/blocks.php b/lib/ajax/blocks.php
index 041190ad91b..470106d071c 100644
--- a/lib/ajax/blocks.php
+++ b/lib/ajax/blocks.php
@@ -30,6 +30,7 @@ require_once(dirname(__FILE__) . '/../../config.php');
 $courseid = required_param('courseid', PARAM_INT);
 $pagelayout = required_param('pagelayout', PARAM_ALPHAEXT);
 $pagetype = required_param('pagetype', PARAM_ALPHAEXT);
+$subpage = optional_param('subpage', '', PARAM_ALPHANUMEXT);
 $cmid = optional_param('cmid', null, PARAM_INT);
 $action = optional_param('action', '', PARAM_ALPHA);
 // Params for blocks-move actions
@@ -51,6 +52,7 @@ require_sesskey();
 
 // Setting layout to replicate blocks configuration for the page we edit
 $PAGE->set_pagelayout($pagelayout);
+$PAGE->set_subpage($subpage);
 echo $OUTPUT->header(); // send headers
 
 switch ($action) {
diff --git a/lib/yui/blocks/blocks.js b/lib/yui/blocks/blocks.js
index 0975b879f9f..edb655fa048 100644
--- a/lib/yui/blocks/blocks.js
+++ b/lib/yui/blocks/blocks.js
@@ -99,7 +99,13 @@ YUI.add('moodle-core-blocks', function(Y) {
         },
 
         get_block_region : function(node) {
-            return node.ancestor('div.'+CSS.BLOCKREGION).get('id').replace(/region/i, 'side');
+            var region = node.ancestor('div.'+CSS.BLOCKREGION).get('id').replace(/region-/i, '');
+            if (Y.Array.indexOf(this.get('regions'), region) === -1) {
+                // Must be standard side-X
+                return 'side-' + region;
+            }
+            // Perhaps custom region
+            return region;
         },
 
         get_region_id : function(node) {
@@ -207,6 +213,7 @@ YUI.add('moodle-core-blocks', function(Y) {
                 courseid : this.get('courseid'),
                 pagelayout : this.get('pagelayout'),
                 pagetype : this.get('pagetype'),
+                subpage : this.get('subpage'),
                 action : 'move',
                 bui_moveid : this.get_block_id(dragnode),
                 bui_newregion : this.get_block_region(dropnode)
@@ -262,6 +269,9 @@ YUI.add('moodle-core-blocks', function(Y) {
             pagetype : {
                 value : null
             },
+            subpage : {
+                value : null
+            },
             regions : {
                 value : null
             }