diff --git a/VERSION b/VERSION
index 42de374..672e5f5 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.0.40
+1.0.39
diff --git a/iyzipay/iyzipay_resource.py b/iyzipay/iyzipay_resource.py
index 7111381..89b4ad7 100644
--- a/iyzipay/iyzipay_resource.py
+++ b/iyzipay/iyzipay_resource.py
@@ -16,7 +16,7 @@ class IyzipayResource:
     header = {
         "Accept": "application/json", 
         "Content-type": "application/json",
-        'x-iyzi-client-version': 'iyzipay-python-1.0.40'
+        'x-iyzi-client-version': 'iyzipay-python-1.0.39'
     }
 
     def __init__(self):
diff --git a/setup.py b/setup.py
index 24e0d9e..3646bc8 100755
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,7 @@
 
 setup(
     name='iyzipay',
-    version='1.0.40',
+    version='1.0.39',
     use_scm_version=True,
     setup_requires=['setuptools_scm', 'future'],
     description='iyzipay api python client',