diff --git a/tests/Zendesk/API/UnitTests/Sell/ContactsTest.php b/tests/Zendesk/API/UnitTests/Sell/ContactsTest.php
index c5539b6d..85996df0 100644
--- a/tests/Zendesk/API/UnitTests/Sell/ContactsTest.php
+++ b/tests/Zendesk/API/UnitTests/Sell/ContactsTest.php
@@ -40,10 +40,20 @@ public function testUpsert()
             ]
         ];
 
+        $encodedQueryParams = [];
+        foreach ($queryParams as $key => $value) {
+            // Don't encode the email address
+            if ($key === 'email') {
+                $encodedQueryParams[$key] = $value;
+                continue;
+            }
+            $encodedQueryParams[$key] = rawurlencode($value);
+        }
+
         $this->assertEndpointCalled(function () use ($queryParams, $postFields) {
             $this->client->sell->contacts()->upsert($queryParams, $postFields);
         }, '/contacts/upsert', 'POST', [
-            'queryParams' => $queryParams,
+            'queryParams' => $encodedQueryParams,
             'postFields'  => ['data' => $postFields],
             'apiBasePath' => '/v2'
         ]);