diff --git a/src/Composer/Package/Version/VersionGuesser.php b/src/Composer/Package/Version/VersionGuesser.php
index bda0f7ec6..9aca9ca53 100644
--- a/src/Composer/Package/Version/VersionGuesser.php
+++ b/src/Composer/Package/Version/VersionGuesser.php
@@ -179,7 +179,7 @@ class VersionGuesser
             }
 
             if (!$isFeatureBranch) {
-                return $version;
+                return array('version' => $version, 'commit' => null, 'pretty_version' => $version);
             }
 
             // re-use the HgDriver to fetch branches (this properly includes bookmarks)
diff --git a/tests/Composer/Test/Package/Version/VersionGuesserTest.php b/tests/Composer/Test/Package/Version/VersionGuesserTest.php
index b3af71cc9..52488dacc 100644
--- a/tests/Composer/Test/Package/Version/VersionGuesserTest.php
+++ b/tests/Composer/Test/Package/Version/VersionGuesserTest.php
@@ -88,7 +88,7 @@ class VersionGuesserTest extends \PHPUnit_Framework_TestCase
         $guesser = new VersionGuesser($config, $executor, new VersionParser());
         $versionArray = $guesser->guessVersion(array(), 'dummy/path');
 
-        $this->assertEquals($branch, $versionArray['version']);
+        $this->assertEquals('dev-' . $branch, $versionArray['version']);
         $this->assertEmpty($versionArray['commit']);
     }