diff --git a/src/Security/InheritedPermissions.php b/src/Security/InheritedPermissions.php
index d8ae2f7bd..adf752429 100644
--- a/src/Security/InheritedPermissions.php
+++ b/src/Security/InheritedPermissions.php
@@ -737,6 +737,7 @@ class InheritedPermissions implements PermissionChecker, MemberCacheFlusher
      */
     protected function generateCacheKey($type, $memberID)
     {
-        return "{$type}-{$memberID}";
+        $classKey = str_replace('\\', '-', $this->baseClass);
+        return "{$type}-{$classKey}-{$memberID}";
     }
 }