diff --git a/lib/ApiRequestor.php b/lib/ApiRequestor.php
index e8f653438..2672ef35e 100644
--- a/lib/ApiRequestor.php
+++ b/lib/ApiRequestor.php
@@ -348,6 +348,7 @@ private static function _defaultHeaders($apiKey, $clientInfo = null)
             'X-Stripe-Client-User-Agent' => \json_encode($ua),
             'User-Agent' => $uaString,
             'Authorization' => 'Bearer ' . $apiKey,
+            'Stripe-Version' => Stripe::getApiVersion(),
         ];
     }
 
@@ -393,9 +394,6 @@ function ($key) use ($params) {
         $absUrl = $this->_apiBase . $url;
         $params = self::_encodeObjects($params);
         $defaultHeaders = $this->_defaultHeaders($myApiKey, $clientUAInfo);
-        if (Stripe::$apiVersion) {
-            $defaultHeaders['Stripe-Version'] = Stripe::$apiVersion;
-        }
 
         if (Stripe::$accountId) {
             $defaultHeaders['Stripe-Account'] = Stripe::$accountId;
diff --git a/lib/BaseStripeClient.php b/lib/BaseStripeClient.php
index aa6a59a37..60c7c5a5f 100644
--- a/lib/BaseStripeClient.php
+++ b/lib/BaseStripeClient.php
@@ -18,6 +18,7 @@ class BaseStripeClient implements StripeClientInterface, StripeStreamingClientIn
         'api_key' => null,
         'client_id' => null,
         'stripe_account' => null,
+        // Note, even if null, ApiRequestor will default this to Stripe::$apiVersion
         'stripe_version' => null,
         'api_base' => self::DEFAULT_API_BASE,
         'connect_base' => self::DEFAULT_CONNECT_BASE,
diff --git a/lib/Stripe.php b/lib/Stripe.php
index 504b13ec8..335f9316e 100644
--- a/lib/Stripe.php
+++ b/lib/Stripe.php
@@ -22,8 +22,8 @@ class Stripe
     /** @var string The base URL for the Stripe API uploads endpoint. */
     public static $apiUploadBase = 'https://files.stripe.com';
 
-    /** @var null|string The version of the Stripe API to use for requests. */
-    public static $apiVersion = null;
+    /** @var string The version of the Stripe API to use for requests. */
+    public static $apiVersion = \Stripe\Util\ApiVersion::CURRENT;
 
     /** @var null|string The account ID for connected accounts requests. */
     public static $accountId = null;
@@ -119,8 +119,7 @@ public static function setClientId($clientId)
     }
 
     /**
-     * @return string The API version used for requests. null if we're using the
-     *    latest version.
+     * @return string the API version used for requests
      */
     public static function getApiVersion()
     {
diff --git a/tests/Stripe/ApiRequestorTest.php b/tests/Stripe/ApiRequestorTest.php
index 6615b12a6..5fbdfa945 100644
--- a/tests/Stripe/ApiRequestorTest.php
+++ b/tests/Stripe/ApiRequestorTest.php
@@ -82,6 +82,11 @@ public function testDefaultHeaders()
             'Stripe/v1 PhpBindings/' . Stripe::VERSION . ' MyTestApp/1.2.34 (https://mytestapp.example)'
         );
 
+        static::assertSame(
+            $headers['Stripe-Version'],
+            Stripe::getApiVersion()
+        );
+
         static::assertSame($headers['Authorization'], 'Bearer ' . $apiKey);
     }
 
diff --git a/tests/TestHelper.php b/tests/TestHelper.php
index 95e4ec64b..06319c7c0 100644
--- a/tests/TestHelper.php
+++ b/tests/TestHelper.php
@@ -43,7 +43,6 @@ protected function setUpConfig()
         Stripe::$apiUploadBase = \defined('MOCK_URL') ? MOCK_URL : 'http://localhost:12111';
         Stripe::setApiKey('sk_test_123');
         Stripe::setClientId('ca_123');
-        Stripe::setApiVersion(null);
         Stripe::setAccountId(null);
 
         // Set up the HTTP client mocker
@@ -63,7 +62,6 @@ protected function tearDownConfig()
         Stripe::setEnableTelemetry(false);
         Stripe::setApiKey($this->origApiKey);
         Stripe::setClientId($this->origClientId);
-        Stripe::setApiVersion($this->origApiVersion);
         Stripe::setAccountId($this->origAccountId);
     }