diff --git a/jquery.pjax.js b/jquery.pjax.js
index 4e2bd0ee..b1648382 100644
--- a/jquery.pjax.js
+++ b/jquery.pjax.js
@@ -191,7 +191,11 @@ function pjax(options) {
   // Without adding this secret parameter, some browsers will often
   // confuse the two.
   if (!options.data) options.data = {}
-  options.data._pjax = context.selector
+  if ($.isArray(options.data)) {
+    options.data.push({name: '_pjax', value: context.selector})
+  } else {
+    options.data._pjax = context.selector
+  }
 
   function fire(type, args, props) {
     if (!props) props = {}
diff --git a/test/unit/pjax.js b/test/unit/pjax.js
index 9767290a..a1992918 100644
--- a/test/unit/pjax.js
+++ b/test/unit/pjax.js
@@ -215,7 +215,7 @@ if ($.support.pjax) {
     })
   })
 
-  asyncTest("sets hidden _pjax param on XHR GET request", function() {
+  asyncTest("sets hidden _pjax param on XHR GET request", 1, function() {
     var frame = this.frame
 
     frame.$('#main').on('pjax:success', function() {
@@ -225,6 +225,43 @@ if ($.support.pjax) {
     })
     frame.$.pjax({
       url: "env.html",
+      data: undefined,
+      container: "#main"
+    })
+  })
+
+  asyncTest("sets hidden _pjax param if array data is supplied", 1, function() {
+    var frame = this.frame
+
+    frame.$('#main').on('pjax:success', function() {
+      var env = JSON.parse(frame.$("#env").text())
+      deepEqual(env['rack.request.query_hash'], {
+        _pjax: '#main',
+        foo: 'bar'
+      })
+      start()
+    })
+    frame.$.pjax({
+      url: "env.html",
+      data: [{ name: "foo", value: "bar" }],
+      container: "#main"
+    })
+  })
+
+  asyncTest("sets hidden _pjax param if object data is supplied", 1, function() {
+    var frame = this.frame
+
+    frame.$('#main').on('pjax:success', function() {
+      var env = JSON.parse(frame.$("#env").text())
+      deepEqual(env['rack.request.query_hash'], {
+        _pjax: '#main',
+        foo: 'bar'
+      })
+      start()
+    })
+    frame.$.pjax({
+      url: "env.html",
+      data: { foo: "bar" },
       container: "#main"
     })
   })