diff --git a/reclass/values/compitem.py b/reclass/values/compitem.py
index 765b323..c6e8863 100644
--- a/reclass/values/compitem.py
+++ b/reclass/values/compitem.py
@@ -39,6 +39,21 @@
     def get_references(self):
         return self._refs
 
+    def merge_over(self, item):
+        if item.type == Item.SCALAR or item.type == Item.COMPOSITE:
+            return self
+        elif item.type == Item.LIST:
+            if self._settings.allow_scalar_over_list or (self._settings.allow_none_override and self._value in [None, 'none', 'None']):
+                return self
+            else:
+                raise TypeError('allow scalar over list = False: cannot merge %s over %s' % (repr(self), repr(item)))
+        elif item.type == Item.DICTIONARY:
+            if self._settings.allow_scalar_over_dict or (self._settings.allow_none_override and self._value in [None, 'none', 'None']):
+                return self
+            else:
+                raise TypeError('allow scalar over dict = False: cannot merge %s over %s' % (repr(self), repr(item)))
+        raise TypeError('Cannot merge %s over %s' % (repr(self), repr(item)))
+
     def render(self, context, inventory):
         # Preserve type if only one item
         if len(self._items) == 1:
diff --git a/reclass/values/scaitem.py b/reclass/values/scaitem.py
index 9de5681..f4265b5 100644
--- a/reclass/values/scaitem.py
+++ b/reclass/values/scaitem.py
@@ -18,7 +18,7 @@
         return self._value
 
     def merge_over(self, item):
-        if item.type == Item.SCALAR:
+        if item.type == Item.SCALAR or item.type == Item.COMPOSITE:
             return self
         elif item.type == Item.LIST:
             if self._settings.allow_scalar_over_list or (self._settings.allow_none_override and self._value is None):