diff --git a/iyzipay/iyzipay_resource.py b/iyzipay/iyzipay_resource.py
index 200cd8b..a8aded3 100644
--- a/iyzipay/iyzipay_resource.py
+++ b/iyzipay/iyzipay_resource.py
@@ -13,7 +13,7 @@ class IyzipayResource:
     header = {
         "Accept": "application/json", 
         "Content-type": "application/json",
-        'x-iyzi-client-version': 'iyzipay-python-1.0.44'
+        'x-iyzi-client-version': 'iyzipay-python-1.0.43'
     }
 
     def __init__(self):