diff --git a/InvenTree/InvenTree/helpers.py b/InvenTree/InvenTree/helpers.py
index 3032b328bd..6dad393349 100644
--- a/InvenTree/InvenTree/helpers.py
+++ b/InvenTree/InvenTree/helpers.py
@@ -315,7 +315,7 @@ def WrapWithQuotes(text, quote='"'):
     return text
 
 
-def MakeBarcode(object_name, object_pk, object_data={}, **kwargs):
+def MakeBarcode(object_name, object_pk, object_data=None, **kwargs):
     """ Generate a string for a barcode. Adds some global InvenTree parameters.
 
     Args:
@@ -327,6 +327,8 @@ def MakeBarcode(object_name, object_pk, object_data={}, **kwargs):
     Returns:
         json string of the supplied data plus some other data
     """
+    if object_data is None:
+        object_data = {}
 
     url = kwargs.get('url', False)
     brief = kwargs.get('brief', True)
diff --git a/InvenTree/stock/models.py b/InvenTree/stock/models.py
index 140bd9c8e3..8a68eb5940 100644
--- a/InvenTree/stock/models.py
+++ b/InvenTree/stock/models.py
@@ -1022,7 +1022,7 @@ class StockItem(MPTTModel):
     def has_tracking_info(self):
         return self.tracking_info_count > 0
 
-    def add_tracking_entry(self, entry_type, user, deltas={}, notes='', **kwargs):
+    def add_tracking_entry(self, entry_type, user, deltas=None, notes='', **kwargs):
         """
         Add a history tracking entry for this StockItem
 
@@ -1033,6 +1033,8 @@ class StockItem(MPTTModel):
             notes - User notes associated with this tracking entry
             url - Optional URL associated with this tracking entry
         """
+        if deltas is None:
+            deltas = {}
 
         # Has a location been specified?
         location = kwargs.get('location', None)