diff --git a/tests/test_alter.py b/tests/test_alter.py
new file mode 100644
index 00000000..a78a07f2
--- /dev/null
+++ b/tests/test_alter.py
@@ -0,0 +1,116 @@
+import pytest
+import re
+import datajoint as dj
+from . import schema as schema_any_module, PREFIX
+
+
+class Experiment(dj.Imported):
+    original_definition = """  # information about experiments
+    -> Subject
+    experiment_id  :smallint  # experiment number for this subject
+    ---
+    experiment_date  :date   # date when experiment was started
+    -> [nullable] User
+    data_path=""     :varchar(255)  # file path to recorded data
+    notes=""         :varchar(2048) # e.g. purpose of experiment
+    entry_time=CURRENT_TIMESTAMP :timestamp   # automatic timestamp
+    """
+
+    definition1 = """  # Experiment
+    -> Subject
+    experiment_id  :smallint  # experiment number for this subject
+    ---
+    data_path     : int  # some number
+    extra=null : longblob  # just testing
+    -> [nullable] User
+    subject_notes=null         :varchar(2048) # {notes} e.g. purpose of experiment
+    entry_time=CURRENT_TIMESTAMP :timestamp   # automatic timestamp
+    """
+
+
+class Parent(dj.Manual):
+    definition = """
+    parent_id: int
+    """
+
+    class Child(dj.Part):
+        definition = """
+        -> Parent
+        """
+        definition_new = """
+        -> master
+        ---
+        child_id=null: int
+        """
+
+    class Grandchild(dj.Part):
+        definition = """
+        -> master.Child
+        """
+        definition_new = """
+        -> master.Child
+        ---
+        grandchild_id=null: int
+        """
+
+
+LOCALS_ALTER = {"Experiment": Experiment, "Parent": Parent}
+COMBINED_CONTEXT = {
+    **schema_any_module.LOCALS_ANY,
+    **LOCALS_ALTER,
+}
+
+
+@pytest.fixture
+def schema_alter(connection_test, schema_any):
+    # Overwrite Experiment and Parent nodes
+    schema_any(Experiment, context=LOCALS_ALTER)
+    schema_any(Parent, context=LOCALS_ALTER)
+    yield schema_any
+    schema_any.drop()
+
+
+class TestAlter:
+    def test_alter(self, schema_alter):
+        original = schema_alter.connection.query(
+            "SHOW CREATE TABLE " + Experiment.full_table_name
+        ).fetchone()[1]
+        Experiment.definition = Experiment.definition1
+        Experiment.alter(prompt=False, context=COMBINED_CONTEXT)
+        altered = schema_alter.connection.query(
+            "SHOW CREATE TABLE " + Experiment.full_table_name
+        ).fetchone()[1]
+        assert original != altered
+        Experiment.definition = Experiment.original_definition
+        Experiment().alter(prompt=False, context=COMBINED_CONTEXT)
+        restored = schema_alter.connection.query(
+            "SHOW CREATE TABLE " + Experiment.full_table_name
+        ).fetchone()[1]
+        assert altered != restored
+        assert original == restored
+
+    def verify_alter(self, schema_alter, table, attribute_sql):
+        definition_original = schema_alter.connection.query(
+            f"SHOW CREATE TABLE {table.full_table_name}"
+        ).fetchone()[1]
+        table.definition = table.definition_new
+        table.alter(prompt=False)
+        definition_new = schema_alter.connection.query(
+            f"SHOW CREATE TABLE {table.full_table_name}"
+        ).fetchone()[1]
+        assert (
+            re.sub(f"{attribute_sql},\n  ", "", definition_new) == definition_original
+        )
+
+    def test_alter_part(self, schema_alter):
+        """
+        https://github.com/datajoint/datajoint-python/issues/936
+        """
+        self.verify_alter(
+            schema_alter, table=Parent.Child, attribute_sql="`child_id` .* DEFAULT NULL"
+        )
+        self.verify_alter(
+            schema_alter,
+            table=Parent.Grandchild,
+            attribute_sql="`grandchild_id` .* DEFAULT NULL",
+        )