diff --git a/index.js b/index.js
index 65f663b..e1e97ad 100644
--- a/index.js
+++ b/index.js
@@ -13,9 +13,11 @@ exports.quote = function (xs) {
 };
 
 exports.parse = function parse (s, env) {
-    if (!env) env = {};
     var chunker = /(['"])((\\\1|[^\1])*?)\1|(\\ |\S)+/g;
-    return s.match(chunker).map(function (s) {
+    var match = s.match(chunker);
+    if (!match) return [];
+    if (!env) env = {};
+    return match.map(function (s) {
         if (/^'/.test(s)) {
             return s
                 .replace(/^'|'$/g, '')
diff --git a/test/parse.js b/test/parse.js
index d52b781..075f1f8 100644
--- a/test/parse.js
+++ b/test/parse.js
@@ -10,6 +10,9 @@ test('parse shell commands', function (t) {
     t.same(parse('a b\\ c d'), [ 'a', 'b c', 'd' ]);
     t.same(parse('\\$beep bo\\`op'), [ '$beep', 'bo`op' ]);
     t.same(parse('echo "foo = \\"foo\\""'), [ 'echo', 'foo = "foo"' ]);
+    t.same(parse(''), []);
+    t.same(parse(' '), []);
+    t.same(parse("\t"), []);
     
     t.end();
 });
diff --git a/test/quote.js b/test/quote.js
index d6146e4..b828ad0 100644
--- a/test/quote.js
+++ b/test/quote.js
@@ -11,5 +11,6 @@ test('quote', function (t) {
         quote([ '$', '`', '\'' ]),
         '\\$ \\` "\'"'
     );
+    t.equal(quote([]), '');
     t.end();
 });