diff --git a/lib/cmd/test.js b/lib/cmd/test.js
index 19e60623..7b95607c 100644
--- a/lib/cmd/test.js
+++ b/lib/cmd/test.js
@@ -27,6 +27,7 @@ class TestCommand extends Command {
         type: 'number',
       },
       'full-trace': {
+        type: 'boolean',
         description: 'display the full stack trace',
       },
       changed: {