diff --git a/packages/ckeditor5-build-trilium/src/config.ts b/packages/ckeditor5-build-trilium/src/config.ts
index 23b656823..09cbaceb9 100644
--- a/packages/ckeditor5-build-trilium/src/config.ts
+++ b/packages/ckeditor5-build-trilium/src/config.ts
@@ -233,7 +233,8 @@ export const COMMON_SETTINGS = {
 		}
 	},
 	link: {
-		defaultProtocol: 'https://'
+		defaultProtocol: 'https://',
+		allowedProtocols: ['https?', 'tel', 'sms', 'sftp', 'smb', 'slack', 'file', 'zotero']
 	},
 	// This value must be kept in sync with the language defined in webpack.config.js.
 	language: 'en'