diff --git a/src/Curl/ArrayUtil.php b/src/Curl/ArrayUtil.php
index f73eedc..217effa 100644
--- a/src/Curl/ArrayUtil.php
+++ b/src/Curl/ArrayUtil.php
@@ -14,7 +14,7 @@ class ArrayUtil
      */
     public static function isArrayAssoc($array)
     {
-        return (bool)count(array_filter(array_keys($array), 'is_string'));
+        return is_array($array) && (bool)count(array_filter(array_keys($array), 'is_string'));
     }
 
     /**