diff --git a/src/goals/PackageGoal.php b/src/goals/PackageGoal.php
index 806b53b..e7f9b8a 100644
--- a/src/goals/PackageGoal.php
+++ b/src/goals/PackageGoal.php
@@ -63,7 +63,7 @@ public function getNamespace()
 
     public static function defaultNamespace($vendor, $package)
     {
-        return $vendor . '\\' . strtr($package, '-', '\\');
+        return preg_replace('/[^a-zA-Z0-9\\\\]+/', '', $vendor . strtr("-$package", '-', '\\'));
     }
 
     public function getSrc()