diff --git a/src/Composer/Util/StreamContextFactory.php b/src/Composer/Util/StreamContextFactory.php
index e62bb7e52..781fda6ae 100644
--- a/src/Composer/Util/StreamContextFactory.php
+++ b/src/Composer/Util/StreamContextFactory.php
@@ -58,7 +58,7 @@ final class StreamContextFactory
     /**
      * @param string $url
      * @param array $options
-     * @param bool $forCurl
+     * @param bool $forCurl When true, will not add proxy values as these are handled separately
      * @psalm-return array{http:{header: string[], proxy?: string, request_fulluri: bool}, ssl: array}
      * @return array formatted as a stream context array
      */
@@ -75,13 +75,17 @@ final class StreamContextFactory
         // Add stream proxy options if there is a proxy
         if (!$forCurl) {
             $proxy = ProxyManager::getInstance()->getProxyForRequest($url);
+            $isHttpsRequest = 0 === strpos($url, 'https://');
+
             if ($proxy->isSecure()) {
                 if (!extension_loaded('openssl')) {
-                    throw new TransportException('You must enable the openssl extension to use a proxy over https.');
+                    throw new TransportException('You must enable the openssl extension to use a secure proxy.');
                 }
-                if (0 === strpos($url, 'https://')) {
-                    throw new TransportException('PHP does not support https requests to a secure proxy.');
+                if ($isHttpsRequest) {
+                    throw new TransportException('You must enable the curl extension to make https requests through a secure proxy.');
                 }
+            } elseif ($isHttpsRequest && !extension_loaded('openssl')) {
+                throw new TransportException('You must enable the openssl extension to make https requests through a proxy.');
             }
 
             $proxyOptions = $proxy->getContextOptions();
diff --git a/tests/Composer/Test/Util/StreamContextFactoryTest.php b/tests/Composer/Test/Util/StreamContextFactoryTest.php
index 80423a825..c28b95b1a 100644
--- a/tests/Composer/Test/Util/StreamContextFactoryTest.php
+++ b/tests/Composer/Test/Util/StreamContextFactoryTest.php
@@ -226,6 +226,10 @@ class StreamContextFactoryTest extends TestCase
 
     public function testInitOptionsForCurlDoesNotIncludeProxyAuthHeaders()
     {
+        if (!extension_loaded('curl')) {
+            $this->markTestSkipped('The curl is not available.');
+        }
+
         $_SERVER['http_proxy'] = 'http://username:password@proxyserver.net:3128/';
 
         $options = array();