diff --git a/src/js/controller.js b/src/js/controller.js
index f9de926..b85608e 100644
--- a/src/js/controller.js
+++ b/src/js/controller.js
@@ -5,7 +5,7 @@ angular.module('focaModalEfectivo')
             '$uibModalInstance',
             function($scope, $uibModalInstance) {
                 $scope.aceptar = function(key) {
-                    if(key === 13) {
+                    if(key === 13 && $scope.efectivo) {
                         var efectivo = parseFloat($scope.efectivo);
                         $uibModalInstance.close(efectivo);
                     }