diff --git a/blocks/dock.js b/blocks/dock.js
index a759913..1c01121 100644
--- a/blocks/dock.js
+++ b/blocks/dock.js
@@ -565,7 +565,7 @@ M.core_dock.resizeBlockSpace = function(node) {
         if (hasblocks) {
             populatedblockregions++;
         }
-        blockregions[region.get('id')] = {hasblocks: hasblocks, bodyclass: region.get('id').replace(/^region\-/, 'side-')+'-only'};
+        blockregions[region.get('id')] = {hasblocks: hasblocks, bodyclass: region.get('id').replace(/([\w-])*region\-/, 'side-')+'-only'};
     });
     var bodynode = M.core_dock.nodes.body;
     var showregions = false;