diff --git a/code/LeftAndMainSubsites.php b/code/LeftAndMainSubsites.php
index ca75c29..12875eb 100644
--- a/code/LeftAndMainSubsites.php
+++ b/code/LeftAndMainSubsites.php
@@ -14,11 +14,19 @@ class LeftAndMainSubsites extends Extension {
 		Requirements::javascript('subsites/javascript/LeftAndMain_Subsites.js');
 		Requirements::javascript('subsites/javascript/VirtualPage_Subsites.js');
 		
+		// Switch to the subsite of the current page
 		if ($this->owner->class == 'CMSMain' && $currentPage = $this->owner->currentPage()) {
 			if (Subsite::currentSubsiteID() != $currentPage->SubsiteID) {
 				Subsite::changeSubsite($currentPage->SubsiteID);
 			}
 		}
+		
+		// Switch to a subsite that this user can actually access.
+		$sites = Subsite::accessible_sites("CMS_ACCESS_{$this->owner->class}")->toDropdownMap();
+		if(!isset($sites[Subsite::currentSubsiteID()])) {
+			$siteIDs = array_keys($sites);
+			Subsite::changeSubsite($siteIDs[0]);
+		}
 	}
 	
 	/**