diff --git a/mlair/data_handler/data_handler_single_station.py b/mlair/data_handler/data_handler_single_station.py
index c5b3ae8d9168156be3c9e5cef66644a7a15a789e..cb0a4803b7dd5825c7c3a63622766a02ce40811b 100644
--- a/mlair/data_handler/data_handler_single_station.py
+++ b/mlair/data_handler/data_handler_single_station.py
@@ -702,6 +702,12 @@ class DataHandlerSingleStation(AbstractDataHandler):
         :param inverse:
         :return:
         """
+        pos = self.get_transformation_base(base)
+        return self.transform(data, dim=dim, opts=self._transformation[pos], inverse=inverse,
+                              transformation_dim=self.target_dim)
+
+    @staticmethod
+    def get_transformation_base(base):
         if base in ["target", 1]:
             pos = 1
         elif base in ["input", 0]:
@@ -710,8 +716,7 @@ class DataHandlerSingleStation(AbstractDataHandler):
             raise ValueError("apply transformation requires a reference for transformation options. Please specify if"
                              "you want to use input or target transformation using the parameter 'base'. Given was: " +
                              base)
-        return self.transform(data, dim=dim, opts=self._transformation[pos], inverse=inverse,
-                              transformation_dim=self.target_dim)
+        return pos
 
     def _hash_list(self):
         return sorted(list(set(self._hash)))