diff --git a/lib/iris/fileformats/_nc_load_rules/helpers.py b/lib/iris/fileformats/_nc_load_rules/helpers.py
index bbf9c660c5..f30da59e87 100644
--- a/lib/iris/fileformats/_nc_load_rules/helpers.py
+++ b/lib/iris/fileformats/_nc_load_rules/helpers.py
@@ -433,9 +433,9 @@ def build_cube_metadata(engine):
     # Set the cube global attributes.
     for attr_name, attr_value in cf_var.cf_group.global_attributes.items():
         try:
-            cube.attributes[str(attr_name)] = attr_value
+            cube.attributes.globals[str(attr_name)] = attr_value
         except ValueError as e:
-            msg = "Skipping global attribute {!r}: {}"
+            msg = "Skipping disallowed global attribute {!r}: {}"
             warnings.warn(msg.format(attr_name, str(e)))
 
 
diff --git a/lib/iris/fileformats/netcdf/loader.py b/lib/iris/fileformats/netcdf/loader.py
index 20d255ea44..dfdcd990dc 100644
--- a/lib/iris/fileformats/netcdf/loader.py
+++ b/lib/iris/fileformats/netcdf/loader.py
@@ -159,8 +159,13 @@ def attribute_predicate(item):
         return item[0] not in _CF_ATTRS
 
     tmpvar = filter(attribute_predicate, cf_var.cf_attrs_unused())
+    attrs_dict = iris_object.attributes
+    if hasattr(attrs_dict, "locals"):
+        # Treat cube attributes (i.e. a CubeAttrsDict) as a special case.
+        # These attrs are "local" (i.e. on the variable), so record them as such.
+        attrs_dict = attrs_dict.locals
     for attr_name, attr_value in tmpvar:
-        _set_attributes(iris_object.attributes, attr_name, attr_value)
+        _set_attributes(attrs_dict, attr_name, attr_value)
 
 
 def _get_actual_dtype(cf_var):
diff --git a/lib/iris/tests/unit/fileformats/nc_load_rules/helpers/test_build_cube_metadata.py b/lib/iris/tests/unit/fileformats/nc_load_rules/helpers/test_build_cube_metadata.py
index a13fa6cca0..dfe0379a16 100644
--- a/lib/iris/tests/unit/fileformats/nc_load_rules/helpers/test_build_cube_metadata.py
+++ b/lib/iris/tests/unit/fileformats/nc_load_rules/helpers/test_build_cube_metadata.py
@@ -42,7 +42,7 @@ def _make_engine(global_attributes=None, standard_name=None, long_name=None):
     return engine
 
 
-class TestInvalidGlobalAttributes(tests.IrisTest):
+class TestGlobalAttributes(tests.IrisTest):
     def test_valid(self):
         global_attributes = {
             "Conventions": "CF-1.5",
@@ -51,7 +51,7 @@ def test_valid(self):
         engine = _make_engine(global_attributes)
         build_cube_metadata(engine)
         expected = global_attributes
-        self.assertEqual(engine.cube.attributes, expected)
+        self.assertEqual(engine.cube.attributes.globals, expected)
 
     def test_invalid(self):
         global_attributes = {
@@ -65,13 +65,14 @@ def test_invalid(self):
         # Check for a warning.
         self.assertEqual(warn.call_count, 1)
         self.assertIn(
-            "Skipping global attribute 'calendar'", warn.call_args[0][0]
+            "Skipping disallowed global attribute 'calendar'",
+            warn.call_args[0][0],
         )
         # Check resulting attributes. The invalid entry 'calendar'
         # should be filtered out.
         global_attributes.pop("calendar")
         expected = global_attributes
-        self.assertEqual(engine.cube.attributes, expected)
+        self.assertEqual(engine.cube.attributes.globals, expected)
 
 
 class TestCubeName(tests.IrisTest):