diff --git a/lib/utils/validation-utils.js b/lib/utils/validation-utils.js
--- a/lib/utils/validation-utils.js
+++ b/lib/utils/validation-utils.js
@@ -108,7 +108,9 @@
 
 const ashoatKeyserverID = '256';
 
-const idSchemaRegex = '(?:[0-9]+\\|)?[0-9]+';
+const uuidRegex =
+  '[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}';
+const idSchemaRegex = `(?:(?:[0-9]+|${uuidRegex})\\|)?(?:[0-9]+|${uuidRegex})`;
 
 const pendingThreadIDRegex = `pending/(type[0-9]+/[0-9]+(\\+[0-9]+)*|sidebar/${idSchemaRegex})`;