diff --git a/lib/cli/commands-schema.js b/lib/cli/commands-schema.js
index dc4099906..89a280146 100644
--- a/lib/cli/commands-schema.js
+++ b/lib/cli/commands-schema.js
@@ -377,7 +377,7 @@ commands.set('rollback', {
   usage: 'Rollback the Serverless service to a specific deployment',
   options: {
     timestamp: {
-      type: 'string',
+      type: 'number',
       usage: 'Timestamp of the deployment (list deployments with `serverless deploy list`)',
       shortcut: 't',
       required: false,