diff --git a/pyaedt/application/Analysis3DLayout.py b/pyaedt/application/Analysis3DLayout.py
index 932296c4ae9..e62a71e73d8 100644
--- a/pyaedt/application/Analysis3DLayout.py
+++ b/pyaedt/application/Analysis3DLayout.py
@@ -340,7 +340,7 @@ def get_next_xtalk_list(self, trlist=[], tx_prefix=""):
         return next
 
     @pyaedt_function_handler()
-    def get_fext_xtalk_list(self, trlist=[], reclist=[], tx_prefix="", rx_prefix="", skip_same_index_couples=True):
+    def get_fext_xtalk_list(self, trlist=None, reclist=None, tx_prefix="", rx_prefix="", skip_same_index_couples=True):
         """Retrieve a list of all the far end XTalks from two lists of exctitations (driver and receiver).
 
         Parameters
@@ -371,9 +371,9 @@ def get_fext_xtalk_list(self, trlist=[], reclist=[], tx_prefix="", rx_prefix="",
         >>> oModule.GetAllPorts
         """
         fext = []
-        if not trlist:
+        if trlist is None:
             trlist = [i for i in self.excitations if tx_prefix in i]
-        if not reclist:
+        if reclist is None:
             reclist = [i for i in self.excitations if rx_prefix in i]
         for i in trlist:
             for k in reclist:
diff --git a/pyaedt/application/AnalysisNexxim.py b/pyaedt/application/AnalysisNexxim.py
index 716fb0fc605..ef087ec72bd 100644
--- a/pyaedt/application/AnalysisNexxim.py
+++ b/pyaedt/application/AnalysisNexxim.py
@@ -526,15 +526,10 @@ def get_fext_xtalk_list(self, trlist=None, reclist=None, tx_prefix="", rx_prefix
 
         >>> oEditor.GetAllPorts
         """
-        if trlist == None:
-            trlist = []
-        if reclist == None:
-            reclist = []
-
         fext = []
-        if not trlist:
+        if trlist is None:
             trlist = [i for i in list(self.excitations.keys()) if tx_prefix in i]
-        if not reclist:
+        if reclist is None:
             reclist = [i for i in list(self.excitations.keys()) if rx_prefix in i]
         for i in trlist:
             for k in reclist: