diff --git a/ActiveRecord.php b/ActiveRecord.php
index 845e5a098..407c1bdad 100644
--- a/ActiveRecord.php
+++ b/ActiveRecord.php
@@ -323,9 +323,11 @@ public static function buildKey($key)
             }
             ksort($key); // ensure order is always the same
             $isNumeric = true;
-            foreach ($key as $value) {
+            foreach ($key as &$value) {
                 if (!is_numeric($value)) {
                     $isNumeric = false;
+                } else {
+                    $value = (string) $value;
                 }
             }
             if ($isNumeric) {
diff --git a/tests/ActiveRecordTest.php b/tests/ActiveRecordTest.php
index ad9593c59..4f8b8002a 100644
--- a/tests/ActiveRecordTest.php
+++ b/tests/ActiveRecordTest.php
@@ -10,6 +10,7 @@
 use yiiunit\extensions\redis\data\ar\Item;
 use yiiunit\extensions\redis\data\ar\OrderItemWithNullFK;
 use yiiunit\extensions\redis\data\ar\OrderWithNullFK;
+use yiiunit\extensions\redis\data\ar\OrderWithStringAndIntegerPK;
 use yiiunit\framework\ar\ActiveRecordTestTrait;
 
 /**
@@ -141,6 +142,10 @@ public function setUp()
         $orderItem->setAttributes(['order_id' => 3, 'item_id' => 2, 'quantity' => 1, 'subtotal' => 40.0], false);
         $orderItem->save(false);
 
+        $order = new OrderWithStringAndIntegerPK();
+        $order->setAttributes(['id' => 1, 'type' => 'cash', 'customer_id' => 1, 'created_at' => 1325282384, 'total' => 110.0], false);
+        $order->save(false);
+
     }
 
     public function testFindEagerViaRelationPreserveOrder()
@@ -368,6 +373,25 @@ public function testFilterWhereRecursively()
         $this->assertEquals(['and', ['id' => 1]], $query->where);
     }
 
+    public function testStringAndIntPkSaving() {
+        $order = OrderWithStringAndIntegerPK::findOne([
+            'id' => 1,
+            'type' => 'cash',
+        ]);
+
+        $this->assertEquals(110.0, $order->total);
+
+        $order->total = 200.0;
+        $order->save(false);
+
+        $order = OrderWithStringAndIntegerPK::findOne([
+            'id' => 1,
+            'type' => 'cash',
+        ]);
+
+        $this->assertEquals(200.0, $order->total);
+    }
+
     public function testAutoIncrement()
     {
         Customer::getDb()->executeCommand('FLUSHDB');
diff --git a/tests/data/ar/OrderWithStringAndIntegerPK.php b/tests/data/ar/OrderWithStringAndIntegerPK.php
new file mode 100644
index 000000000..114571ca6
--- /dev/null
+++ b/tests/data/ar/OrderWithStringAndIntegerPK.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace yiiunit\extensions\redis\data\ar;
+
+/**
+ * Class Order
+ *
+ * @property integer $id
+ * @property string $type
+ * @property integer $customer_id
+ * @property integer $created_at
+ * @property string $total
+ */
+class OrderWithStringAndIntegerPK extends ActiveRecord
+{
+    public static function primaryKey()
+    {
+        return ['type', 'id'];
+    }
+
+    public function attributes()
+    {
+        return ['id', 'type', 'customer_id', 'created_at', 'total'];
+    }
+}