diff --git a/src/acom_music_box/evolving_conditions.py b/src/acom_music_box/evolving_conditions.py
index 23f2a8fd..9d689ded 100644
--- a/src/acom_music_box/evolving_conditions.py
+++ b/src/acom_music_box/evolving_conditions.py
@@ -26,7 +26,7 @@ def __init__(self, headers=None, times=None, conditions=None):
         self.conditions = conditions if conditions is not None else []
 
     @classmethod
-    def from_UI_JSON(self, UI_JSON, species_list, reaction_list):
+    def from_UI_JSON(cls, UI_JSON, species_list, reaction_list):
         """
         Create a new instance of the EvolvingConditions class from a JSON object.
 
@@ -95,11 +95,10 @@ def from_UI_JSON(self, UI_JSON, species_list, reaction_list):
                     concentrations,
                     rates))
 
-        return self(headers, times, conditions)
+        return cls(headers, times, conditions)
 
-    @classmethod
+    @staticmethod
     def from_config_JSON(
-            self,
             path_to_json,
             config_JSON):
         """