diff --git a/src/Composer/Package/Loader/ArrayLoader.php b/src/Composer/Package/Loader/ArrayLoader.php
index ae5678375..475fd122c 100644
--- a/src/Composer/Package/Loader/ArrayLoader.php
+++ b/src/Composer/Package/Loader/ArrayLoader.php
@@ -58,7 +58,10 @@ class ArrayLoader
             $package->setExtra($config['extra']);
         }
 
-        if (isset($config['bin']) && is_array($config['bin'])) {
+        if (isset($config['bin'])) {
+            if (!is_array($config['bin'])) {
+                throw new \UnexpectedValueException('Package '.$config['name'].'\'s bin key should be an array, '.gettype($config['bin']).' given.');
+            }
             foreach ($config['bin'] as $key => $bin) {
                 $config['bin'][$key]= ltrim($bin, '/');
             }