diff --git a/lib/parse.js b/lib/parse.js
index 04493e1d..53c30dbc 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -83,7 +83,7 @@ var parseValues = function parseQueryStringValues(str, options) {
             val = interpretNumericEntities(val);
         }
 
-        if (val && options.comma && val.indexOf(',') > -1) {
+        if (val && typeof val === 'string' && options.comma && val.indexOf(',') > -1) {
             val = val.split(',');
         }
 
diff --git a/test/parse.js b/test/parse.js
index 9ea38dd3..cda69284 100644
--- a/test/parse.js
+++ b/test/parse.js
@@ -400,6 +400,35 @@ test('parse()', function (t) {
         st.end();
     });
 
+    t.test('use numbers decoder and parses string with comma as array divider',
+        function (st) {
+            var decoder = function (str, defaultDecoder, charset, type) {
+                if (!isNaN(str)) {
+                    return parseFloat(str);
+                }
+
+                if (str && typeof str === 'string' && str.indexOf(',') > -1) {
+                    return str.split(',').map(function (item) {
+                        if (!isNaN(item)) {
+                            return parseFloat(item);
+                        }
+                        return defaultDecoder(item, defaultDecoder, charset, type);
+                    });
+                }
+
+                return defaultDecoder(str, defaultDecoder, charset, type);
+            };
+            st.deepEqual(qs.parse('foo[bar]=1.2,1.5', { comma: true, decoder: decoder }), {
+                foo: { bar: [1.2, 1.5] }
+            });
+            st.deepEqual(qs.parse('foo=1,2', { comma: true, decoder: decoder }), { foo: [1, 2] });
+            st.deepEqual(qs.parse('foo=1.2,2.3', { comma: true, decoder: decoder }), { foo: [1.2, 2.3] });
+            st.deepEqual(qs.parse('foo', { comma: true, strictNullHandling: true, decoder: decoder }), { foo: null });
+
+            st.end();
+        }
+    );
+
     t.test('parses an object in dot notation', function (st) {
         var input = {
             'user.name': { 'pop[bob]': 3 },