diff --git a/InvenTree/common/serializers.py b/InvenTree/common/serializers.py
index 4a27e3f30e..60eb609dc1 100644
--- a/InvenTree/common/serializers.py
+++ b/InvenTree/common/serializers.py
@@ -45,6 +45,18 @@ class SettingsSerializer(InvenTreeModelSerializer):
 
         return results
 
+    def get_value(self, obj):
+        """
+        Make sure protected values are not returned
+        """
+        result = obj.value
+
+        # never return protected values
+        if obj.is_protected:
+            result = '***'
+
+        return result
+
 
 class GlobalSettingsSerializer(SettingsSerializer):
     """
diff --git a/InvenTree/part/bom.py b/InvenTree/part/bom.py
index fd31aba339..1fc747655d 100644
--- a/InvenTree/part/bom.py
+++ b/InvenTree/part/bom.py
@@ -59,7 +59,7 @@ def ExportBom(part, fmt='csv', cascade=False, max_levels=None, parameter_data=Fa
 
     uids = []
 
-    def add_items(items, level, cascade):
+    def add_items(items, level, cascade=True):
         # Add items at a given layer
         for item in items:
 
diff --git a/InvenTree/part/models.py b/InvenTree/part/models.py
index cec21becc2..638c956ffa 100644
--- a/InvenTree/part/models.py
+++ b/InvenTree/part/models.py
@@ -1587,7 +1587,7 @@ class Part(MPTTModel):
         # Exclude any parts that this part is used *in* (to prevent recursive BOMs)
         used_in = self.get_used_in().all()
 
-        parts = parts.exclude(id__in=[item.part.id for item in used_in])
+        parts = parts.exclude(id__in=[part.id for part in used_in])
 
         return parts