diff --git a/src/Composer/Command/InitCommand.php b/src/Composer/Command/InitCommand.php
index b1e778daa..02902adf7 100644
--- a/src/Composer/Command/InitCommand.php
+++ b/src/Composer/Command/InitCommand.php
@@ -35,7 +35,7 @@ class InitCommand extends Command
     public function parseAuthorString($author)
     {
         if (preg_match('/^(?P<name>[- \.,\w\'’]+) <(?P<email>.+?)>$/u', $author, $match)) {
-            if (!function_exists('filter_var') || $match['email'] === filter_var($match['email'], FILTER_VALIDATE_EMAIL)) {
+            if (!function_exists('filter_var') || version_compare(PHP_VERSION, '5.3.3', '<') || $match['email'] === filter_var($match['email'], FILTER_VALIDATE_EMAIL)) {
                 return array(
                     'name'  => trim($match['name']),
                     'email' => $match['email']
diff --git a/src/Composer/Repository/ComposerRepository.php b/src/Composer/Repository/ComposerRepository.php
index f7e021e3e..938e7b566 100644
--- a/src/Composer/Repository/ComposerRepository.php
+++ b/src/Composer/Repository/ComposerRepository.php
@@ -40,7 +40,7 @@ class ComposerRepository extends ArrayRepository implements NotifiableRepository
             $repoConfig['url'] = 'http://'.$repoConfig['url'];
         }
         $repoConfig['url'] = rtrim($repoConfig['url'], '/');
-        if (function_exists('filter_var') && !filter_var($repoConfig['url'], FILTER_VALIDATE_URL)) {
+        if (function_exists('filter_var') && version_compare(PHP_VERSION, '5.3.3', '>=') && !filter_var($repoConfig['url'], FILTER_VALIDATE_URL)) {
             throw new \UnexpectedValueException('Invalid url given for Composer repository: '.$repoConfig['url']);
         }
 
diff --git a/src/Composer/Repository/PearRepository.php b/src/Composer/Repository/PearRepository.php
index 14150d84d..dfd92e00d 100644
--- a/src/Composer/Repository/PearRepository.php
+++ b/src/Composer/Repository/PearRepository.php
@@ -39,7 +39,7 @@ class PearRepository extends ArrayRepository
             $repoConfig['url'] = 'http://'.$repoConfig['url'];
         }
 
-        if (function_exists('filter_var') && !filter_var($repoConfig['url'], FILTER_VALIDATE_URL)) {
+        if (function_exists('filter_var') && version_compare(PHP_VERSION, '5.3.3', '>=') && !filter_var($repoConfig['url'], FILTER_VALIDATE_URL)) {
             throw new \UnexpectedValueException('Invalid url given for PEAR repository: '.$repoConfig['url']);
         }