diff --git a/mlair/model_modules/advanced_paddings.py b/mlair/model_modules/advanced_paddings.py
index 7a16c2b6a0799fd67a7026e14ab046c434a54731..2ada9ee2e9d99044b02924e16a6af4ef35d5e8e7 100644
--- a/mlair/model_modules/advanced_paddings.py
+++ b/mlair/model_modules/advanced_paddings.py
@@ -8,7 +8,6 @@ from typing import Union, Tuple
 
 import numpy as np
 import tensorflow as tf
-from tensorflow.keras import backend as K
 # from tensorflow.keras.backend.common import normalize_data_format
 from tensorflow.keras.layers import ZeroPadding2D
 # from tensorflow.keras.layers.convolutional import _ZeroPadding
@@ -257,7 +256,7 @@ class _ZeroPadding(Layer):
         # self.rank is 1 for ZeroPadding1D, 2 for ZeroPadding2D.
         self.rank = len(padding)
         self.padding = padding
-        self.data_format = K.normalize_data_format(data_format)
+        self.data_format = normalize_data_format(data_format)
         self.input_spec = InputSpec(ndim=self.rank + 2)
         super(_ZeroPadding, self).__init__(**kwargs)