diff --git a/src/Composer/Util/StreamContextFactory.php b/src/Composer/Util/StreamContextFactory.php
index 72d12115d..b25b307a1 100644
--- a/src/Composer/Util/StreamContextFactory.php
+++ b/src/Composer/Util/StreamContextFactory.php
@@ -87,15 +87,15 @@ final class StreamContextFactory
 
             // enabled request_fulluri unless it is explicitly disabled
             switch (parse_url($url, PHP_URL_SCHEME)) {
-                case 'http': // default request_fulluri to true
+                case 'http': // default request_fulluri to true for HTTP
                     $reqFullUriEnv = getenv('HTTP_PROXY_REQUEST_FULLURI');
                     if ($reqFullUriEnv === false || $reqFullUriEnv === '' || (strtolower($reqFullUriEnv) !== 'false' && (bool) $reqFullUriEnv)) {
                         $options['http']['request_fulluri'] = true;
                     }
                     break;
-                case 'https': // default request_fulluri to true
+                case 'https': // default request_fulluri to false for HTTPS
                     $reqFullUriEnv = getenv('HTTPS_PROXY_REQUEST_FULLURI');
-                    if ($reqFullUriEnv === false || $reqFullUriEnv === '' || (strtolower($reqFullUriEnv) !== 'false' && (bool) $reqFullUriEnv)) {
+                    if (strtolower($reqFullUriEnv) !== 'false' && (bool) $reqFullUriEnv) {
                         $options['http']['request_fulluri'] = true;
                     }
                     break;
diff --git a/tests/Composer/Test/Util/StreamContextFactoryTest.php b/tests/Composer/Test/Util/StreamContextFactoryTest.php
index 9bb04aaa1..3d60a9a38 100644
--- a/tests/Composer/Test/Util/StreamContextFactoryTest.php
+++ b/tests/Composer/Test/Util/StreamContextFactoryTest.php
@@ -142,7 +142,6 @@ class StreamContextFactoryTest extends TestCase
         $expected = array(
             'http' => array(
                 'proxy' => 'tcp://proxyserver.net:80',
-                'request_fulluri' => true,
                 'method' => 'GET',
                 'header' => array('User-Agent: foo', "Proxy-Authorization: Basic " . base64_encode('username:password')),
                 'max_redirects' => 20,
@@ -173,7 +172,6 @@ class StreamContextFactoryTest extends TestCase
         $expected = array(
             'http' => array(
                 'proxy' => 'ssl://woopproxy.net:443',
-                'request_fulluri' => true,
                 'method' => 'GET',
                 'max_redirects' => 20,
                 'follow_location' => 1,