diff --git a/packages/@angular/cli/ember-cli/lib/models/command.js b/packages/@angular/cli/ember-cli/lib/models/command.js
index 471f68596150..947e808c7f33 100644
--- a/packages/@angular/cli/ember-cli/lib/models/command.js
+++ b/packages/@angular/cli/ember-cli/lib/models/command.js
@@ -183,7 +183,10 @@ Command.prototype.mergeDuplicateOption = function(key) {
 */
 Command.prototype.normalizeOption = function(option) {
   option.key = camelize(option.name);
-  option.aliases = (option.aliases || []).concat(camelize(option.name));
+  option.aliases = (option.aliases || []);
+  if (option.aliases.indexOf(camelize(option.name)) === -1) {
+    option.aliases = option.aliases.concat(camelize(option.name));
+  }
   option.required = option.required || false;
   return option;
 };