diff --git a/bin/_mocha b/bin/_mocha
index 4873dc741f..f8068835f6 100755
--- a/bin/_mocha
+++ b/bin/_mocha
@@ -82,8 +82,7 @@ program
   .option('--debug-brk', "enable node's debugger breaking on the first line")
   .option('--globals <names>', 'allow the given comma-delimited global [names]', list, [])
   .option('--es_staging', 'enable all staged features')
-  .option('--harmony', 'enable all harmony features (except typeof)')
-  .option('--harmony_<classes,generators,...>', 'all node --harmony* flags are available')
+  .option('--harmony<_classes,_generators,...>', 'all node --harmony* flags are available')
   .option('--inline-diffs', 'display actual/expected differences inline within each string')
   .option('--interfaces', 'display available interfaces')
   .option('--no-deprecation', 'silence deprecation warnings')