diff --git a/src/Composer/Package/Loader/RootPackageLoader.php b/src/Composer/Package/Loader/RootPackageLoader.php
index 64880d727..250f2952f 100644
--- a/src/Composer/Package/Loader/RootPackageLoader.php
+++ b/src/Composer/Package/Loader/RootPackageLoader.php
@@ -131,7 +131,7 @@ class RootPackageLoader extends ArrayLoader
         $minimumStability = $stabilities[$minimumStability];
         foreach ($requires as $reqName => $reqVersion) {
             // parse explicit stability flags to the most unstable
-            if (preg_match('{^[^,\s]*?@('.implode('|', array_keys($stabilities)).')$}i', $reqVersion, $match)) {
+            if (preg_match('{^[^@]*?@('.implode('|', array_keys($stabilities)).')$}i', $reqVersion, $match)) {
                 $name = strtolower($reqName);
                 $stability = $stabilities[VersionParser::normalizeStability($match[1])];
 
diff --git a/tests/Composer/Test/Package/Loader/RootPackageLoaderTest.php b/tests/Composer/Test/Package/Loader/RootPackageLoaderTest.php
index 51799d053..d1f3be1f8 100644
--- a/tests/Composer/Test/Package/Loader/RootPackageLoaderTest.php
+++ b/tests/Composer/Test/Package/Loader/RootPackageLoaderTest.php
@@ -143,6 +143,7 @@ class RootPackageLoaderTest extends \PHPUnit_Framework_TestCase
                 'foo/bar' => '~2.1.0-beta2',
                 'bar/baz' => '1.0.x-dev as 1.2.0',
                 'qux/quux' => '1.0.*@rc',
+                'zux/complex' => '~1.0,>=1.0.2@dev'
             ),
             'minimum-stability' => 'alpha',
         ));
@@ -151,6 +152,7 @@ class RootPackageLoaderTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals(array(
             'bar/baz' => BasePackage::STABILITY_DEV,
             'qux/quux' => BasePackage::STABILITY_RC,
+            'zux/complex' => BasePackage::STABILITY_DEV,
         ), $package->getStabilityFlags());
     }
 }