diff --git a/packages/docusaurus-plugin-content-docs/src/options.ts b/packages/docusaurus-plugin-content-docs/src/options.ts
index 18180fc1948c..76eaedef09a0 100644
--- a/packages/docusaurus-plugin-content-docs/src/options.ts
+++ b/packages/docusaurus-plugin-content-docs/src/options.ts
@@ -54,7 +54,7 @@ export const DEFAULT_OPTIONS: Omit<PluginOptions, 'id' | 'sidebarPath'> = {
   sidebarCollapsible: true,
   sidebarCollapsed: true,
   breadcrumbs: true,
-  onUnknownTags: 'warn',
+  onUnknownTags: 'throw',
   tagsFilePath: 'tags.yml',
 };