1 files changed, 2 insertions, 2 deletions
diff --git a/lib/utils/string.js b/lib/utils/string.js
index 72a9ca0..caa2364 100644
--- a/lib/utils/string.js
+++ b/lib/utils/string.js
@@ -1,7 +1,7 @@
 var _ = require("lodash");
 
 function escapeShellArg(arg) {
-    var ret = '';
+    var ret = "";
 
     ret = arg.replace(/"/g, '\\"');
 
@@ -11,7 +11,7 @@ function escapeShellArg(arg) {
 function optionsToShellArgs(options) {
     return _.chain(options)
     .map(function(value, key) {
-        if (value == null || value === false) return null;
+        if (value === null || value === undefined || value === false) return null;
         if (value === true) return key;
         return key+"="+escapeShellArg(value);
     })