diff --git a/src/Composer/Downloader/GitDownloader.php b/src/Composer/Downloader/GitDownloader.php
index 177644735..f15539a87 100644
--- a/src/Composer/Downloader/GitDownloader.php
+++ b/src/Composer/Downloader/GitDownloader.php
@@ -146,10 +146,10 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
 
         if (!empty($this->cachedPackages[$target->getId()][$ref])) {
             $msg = "Checking out ".$this->getShortHash($ref).' from cache';
-            $command = 'git rev-parse --quiet --verify %ref% || (git remote set-url composer %cachePath% && git fetch composer && git fetch --tags composer); git remote set-url composer %sanitizedUrl%';
+            $command = '(git rev-parse --quiet --verify %ref% || (git remote set-url composer %cachePath% && git fetch composer && git fetch --tags composer)) && git remote set-url composer %sanitizedUrl%';
         } else {
             $msg = "Checking out ".$this->getShortHash($ref);
-            $command = 'git remote set-url composer %url% && git rev-parse --quiet --verify %ref% || (git fetch composer && git fetch --tags composer); git remote set-url composer %sanitizedUrl%';
+            $command = '(git remote set-url composer %url% && git rev-parse --quiet --verify %ref% || (git fetch composer && git fetch --tags composer)) && git remote set-url composer %sanitizedUrl%';
             if (getenv('COMPOSER_DISABLE_NETWORK')) {
                 throw new \RuntimeException('The required git reference for '.$target->getName().' is not in cache and network is disabled, aborting');
             }
diff --git a/tests/Composer/Test/Downloader/GitDownloaderTest.php b/tests/Composer/Test/Downloader/GitDownloaderTest.php
index 6618618e1..97b6db9ac 100644
--- a/tests/Composer/Test/Downloader/GitDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/GitDownloaderTest.php
@@ -390,7 +390,7 @@ class GitDownloaderTest extends TestCase
 
     public function testUpdate()
     {
-        $expectedGitUpdateCommand = $this->winCompat("git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer); git remote set-url composer 'https://github.com/composer/composer'");
+        $expectedGitUpdateCommand = $this->winCompat("(git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)) && git remote set-url composer 'https://github.com/composer/composer'");
 
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
         $packageMock->expects($this->any())
@@ -421,7 +421,7 @@ class GitDownloaderTest extends TestCase
 
     public function testUpdateWithNewRepoUrl()
     {
-        $expectedGitUpdateCommand = $this->winCompat("git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer); git remote set-url composer 'https://github.com/composer/composer'");
+        $expectedGitUpdateCommand = $this->winCompat("(git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)) && git remote set-url composer 'https://github.com/composer/composer'");
 
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
         $packageMock->expects($this->any())
@@ -496,8 +496,8 @@ composer https://github.com/old/url (push)
      */
     public function testUpdateThrowsRuntimeExceptionIfGitCommandFails()
     {
-        $expectedGitUpdateCommand = $this->winCompat("git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer); git remote set-url composer 'https://github.com/composer/composer'");
-        $expectedGitUpdateCommand2 = $this->winCompat("git remote set-url composer 'git@github.com:composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer); git remote set-url composer 'git@github.com:composer/composer'");
+        $expectedGitUpdateCommand = $this->winCompat("(git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)) && git remote set-url composer 'https://github.com/composer/composer'");
+        $expectedGitUpdateCommand2 = $this->winCompat("(git remote set-url composer 'git@github.com:composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)) && git remote set-url composer 'git@github.com:composer/composer'");
 
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
         $packageMock->expects($this->any())
@@ -540,8 +540,8 @@ composer https://github.com/old/url (push)
 
     public function testUpdateDoesntThrowsRuntimeExceptionIfGitCommandFailsAtFirstButIsAbleToRecover()
     {
-        $expectedFirstGitUpdateCommand = $this->winCompat("git remote set-url composer '".(Platform::isWindows() ? 'C:\\\\' : '/')."' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer); git remote set-url composer '".(Platform::isWindows() ? 'C:\\\\' : '/')."'");
-        $expectedSecondGitUpdateCommand = $this->winCompat("git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer); git remote set-url composer 'https://github.com/composer/composer'");
+        $expectedFirstGitUpdateCommand = $this->winCompat("(git remote set-url composer '".(Platform::isWindows() ? 'C:\\\\' : '/')."' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)) && git remote set-url composer '".(Platform::isWindows() ? 'C:\\\\' : '/')."'");
+        $expectedSecondGitUpdateCommand = $this->winCompat("(git remote set-url composer 'https://github.com/composer/composer' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)) && git remote set-url composer 'https://github.com/composer/composer'");
 
         $packageMock = $this->getMockBuilder('Composer\Package\PackageInterface')->getMock();
         $packageMock->expects($this->any())