diff --git a/src/Composer/Downloader/GitDownloader.php b/src/Composer/Downloader/GitDownloader.php
index af3cb75c9..626676894 100644
--- a/src/Composer/Downloader/GitDownloader.php
+++ b/src/Composer/Downloader/GitDownloader.php
@@ -55,14 +55,12 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
             $this->io->writeError('', true, IOInterface::DEBUG);
             $this->io->writeError(sprintf('    Cloning to cache at %s', ProcessExecutor::escape($cachePath)), true, IOInterface::DEBUG);
             try {
-                $cached = $this->gitUtil->fetchRef($url, $cachePath, $ref);
+                $this->gitUtil->fetchRefOrSyncMirror($url, $cachePath, $ref);
                 if (is_dir($cachePath)) {
                     $command =
                         'git clone --no-checkout %cachePath% %path% --dissociate --reference %cachePath% '
                         . '&& cd '.$flag.'%path% '
                         . '&& git remote set-url origin %url% && git remote add composer %url%';
-                    if (!$cached)
-                        $command .= ' && git fetch composer';
                     $msg = "Cloning ".$this->getShortHash($ref).' from cache';
                 }
             } catch (\RuntimeException $e) {
@@ -120,10 +118,10 @@ class GitDownloader extends VcsDownloader implements DvcsDownloaderInterface
 
         $ref = $target->getSourceReference();
         $this->io->writeError(" Checking out ".$this->getShortHash($ref));
-        $command = 'git remote set-url composer %s && git rev-parse --quiet --verify %s^{commit} || (git fetch composer && git fetch --tags composer)';
+        $command = 'git remote set-url composer %s && git rev-parse --quiet --verify %s || (git fetch composer && git fetch --tags composer)';
 
         $commandCallable = function ($url) use ($command, $ref) {
-            return sprintf($command, ProcessExecutor::escape($url), ProcessExecutor::escape($ref));
+            return sprintf($command, ProcessExecutor::escape($url), ProcessExecutor::escape($ref.'^{commit}'));
         };
 
         $this->gitUtil->runCommand($commandCallable, $url, $path);
diff --git a/src/Composer/Util/Git.php b/src/Composer/Util/Git.php
index fcc83f9f2..e4d6bd803 100644
--- a/src/Composer/Util/Git.php
+++ b/src/Composer/Util/Git.php
@@ -228,33 +228,18 @@ class Git
         return true;
     }
 
-    public function fetchRef($url, $dir, $ref)
+    public function fetchRefOrSyncMirror($url, $dir, $ref)
     {
         if (is_dir($dir) && 0 === $this->process->execute('git rev-parse --git-dir', $output, $dir) && trim($output) === '.') {
-            try {
-                $isTag = $isRef = $actualCommit = false;
-                $escapedRef = ProcessExecutor::escape($ref);
-                $exitCode = $this->process->execute(sprintf('git show-ref --tags %s', $escapedRef), $output, $dir);
-                if (!$exitCode)
-                    $isTag = true;
-                $exitCode = $this->process->execute(sprintf('git show-ref %s', $escapedRef), $output, $dir);
-                if (!$exitCode)
-                    $isRef = true;
-                $exitCode = $this->process->execute(sprintf('git cat-file -t %s', $escapedRef), $output, $dir);
-                if (!$exitCode && trim($output) == "commit")
-                    $actualCommit = true;
-
-                if ($isTag){
-                    return true;
-                }
-                if (!$isRef && $actualCommit) {
-                    return true;
-                }
-            } catch (\Exception $e) {
+            $escapedRef = ProcessExecutor::escape($ref.'^{commit}');
+            $exitCode = $this->process->execute(sprintf('git rev-parse --quiet --verify %s', $escapedRef), $output, $dir);
+            if ($exitCode === 0) {
+                return true;
             }
         }
 
         $this->syncMirror($url, $dir);
+
         return false;
     }
 
diff --git a/tests/Composer/Test/Downloader/GitDownloaderTest.php b/tests/Composer/Test/Downloader/GitDownloaderTest.php
index f5aa4fe9e..20e609712 100644
--- a/tests/Composer/Test/Downloader/GitDownloaderTest.php
+++ b/tests/Composer/Test/Downloader/GitDownloaderTest.php
@@ -173,7 +173,7 @@ class GitDownloaderTest extends TestCase
                 return 0;
             }));
 
-        $expectedGitCommand = $this->winCompat(sprintf("git clone --no-checkout '%1\$s' 'composerPath' --dissociate --reference '%1\$s' && cd 'composerPath' && git remote set-url origin 'https://example.com/composer/composer' && git remote add composer 'https://example.com/composer/composer' && git fetch composer", $cachePath));
+        $expectedGitCommand = $this->winCompat(sprintf("git clone --no-checkout '%1\$s' 'composerPath' --dissociate --reference '%1\$s' && cd 'composerPath' && git remote set-url origin 'https://example.com/composer/composer' && git remote add composer 'https://example.com/composer/composer'", $cachePath));
         $processExecutor->expects($this->at(2))
             ->method('execute')
             ->with($this->equalTo($expectedGitCommand))
@@ -380,7 +380,7 @@ 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)");
+        $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)");
 
         $packageMock = $this->getMock('Composer\Package\PackageInterface');
         $packageMock->expects($this->any())
@@ -429,7 +429,7 @@ 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)");
+        $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)");
 
         $packageMock = $this->getMock('Composer\Package\PackageInterface');
         $packageMock->expects($this->any())
@@ -501,7 +501,7 @@ 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)");
+        $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)");
 
         $packageMock = $this->getMock('Composer\Package\PackageInterface');
         $packageMock->expects($this->any())
@@ -539,8 +539,8 @@ composer https://github.com/old/url (push)
 
     public function testUpdateDoesntThrowsRuntimeExceptionIfGitCommandFailsAtFirstButIsAbleToRecover()
     {
-        $expectedFirstGitUpdateCommand = $this->winCompat("git remote set-url composer '' && git rev-parse --quiet --verify 'ref'^{commit} || (git fetch composer && git fetch --tags composer)");
-        $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)");
+        $expectedFirstGitUpdateCommand = $this->winCompat("git remote set-url composer '' && git rev-parse --quiet --verify 'ref^{commit}' || (git fetch composer && git fetch --tags composer)");
+        $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)");
 
         $packageMock = $this->getMock('Composer\Package\PackageInterface');
         $packageMock->expects($this->any())