diff --git a/lib/cmd/cov.js b/lib/cmd/cov.js
index e123a005..ba18e214 100644
--- a/lib/cmd/cov.js
+++ b/lib/cmd/cov.js
@@ -33,7 +33,7 @@ class CovCommand extends Command {
       'c8-report': {
         description: 'use c8 to report coverage, default to false',
         type: 'boolean',
-        default: false,
+        default: true,
       },
     };