diff --git a/tests/test_errors.py b/tests/test_errors.py
new file mode 100644
index 00000000..3a9fecaa
--- /dev/null
+++ b/tests/test_errors.py
@@ -0,0 +1,56 @@
+import pytest
+import MySQLdb.cursors
+from configdb import connection_factory
+
+
+_conns = []
+_tables = []
+
+
+def connect(**kwargs):
+    conn = connection_factory(**kwargs)
+    _conns.append(conn)
+    return conn
+
+
+def teardown_function(function):
+    if _tables:
+        c = _conns[0]
+        cur = c.cursor()
+        for t in _tables:
+            cur.execute("DROP TABLE {}".format(t))
+        cur.close()
+        del _tables[:]
+
+    for c in _conns:
+        c.close()
+    del _conns[:]
+
+
+def test_null():
+    """Inserting NULL into non NULLABLE column"""
+    # https://github.com/PyMySQL/mysqlclient/issues/535
+    table_name = "test_null"
+    conn = connect()
+    cursor = conn.cursor()
+
+    cursor.execute(f"create table {table_name} (c1 int primary key)")
+    _tables.append(table_name)
+
+    with pytest.raises(MySQLdb.IntegrityError):
+        cursor.execute(f"insert into {table_name} values (null)")
+
+
+def test_duplicated_pk():
+    """Inserting row with duplicated PK"""
+    # https://github.com/PyMySQL/mysqlclient/issues/535
+    table_name = "test_duplicated_pk"
+    conn = connect()
+    cursor = conn.cursor()
+
+    cursor.execute(f"create table {table_name} (c1 int primary key)")
+    _tables.append(table_name)
+
+    cursor.execute(f"insert into {table_name} values (1)")
+    with pytest.raises(MySQLdb.IntegrityError):
+        cursor.execute(f"insert into {table_name} values (1)")