diff --git a/src/HttpBaseTest.php b/src/HttpBaseTest.php
index 4d08f6e..e161ed6 100644
--- a/src/HttpBaseTest.php
+++ b/src/HttpBaseTest.php
@@ -221,7 +221,8 @@ protected function assertResponse($response, array $options = [])
 
         $options = array_merge($this->defaultOptions, $options);
 
-        $this->assertSame($options['protocolVersion'], $response->getProtocolVersion());
+        // The response version may be greater or equal to the request version. See https://tools.ietf.org/html/rfc2145#section-2.3
+        $this->assertTrue(substr($options['protocolVersion'], 0, 1) === substr($response->getProtocolVersion(), 0, 1) && 1 !== version_compare($options['protocolVersion'], $response->getProtocolVersion()));
         $this->assertSame($options['statusCode'], $response->getStatusCode());
         $this->assertSame($options['reasonPhrase'], $response->getReasonPhrase());
 
@@ -253,7 +254,8 @@ protected function assertRequest(
     ) {
         $request = $this->getRequest();
 
-        $this->assertSame($protocolVersion, substr($request['SERVER']['SERVER_PROTOCOL'], 5));
+        $actualProtocolVersion = substr($request['SERVER']['SERVER_PROTOCOL'], 5);
+        $this->assertTrue(substr($protocolVersion, 0, 1) === substr($actualProtocolVersion, 0, 1) && 1 !== version_compare($protocolVersion, $actualProtocolVersion));
         $this->assertSame($method, $request['SERVER']['REQUEST_METHOD']);
 
         $defaultHeaders = [