diff --git a/target_postgres/sql_base.py b/target_postgres/sql_base.py
index 12c2bbe2..9d879526 100644
--- a/target_postgres/sql_base.py
+++ b/target_postgres/sql_base.py
@@ -403,23 +403,30 @@ def upsert_table_helper(self, connection, schema, metadata, log_schema_changes=T
 
             self.add_key_properties(connection, table_name, schema.get('key_properties', None))
 
-            ## Only process columns which have single, nullable, types
-            single_type_columns = []
-            for column_path, column_schema in schema['schema']['properties'].items():
-                for sub_schema in column_schema['anyOf']:
-                    single_type_columns.append((column_path, deepcopy(sub_schema)))
-
-            ## Process new columns against existing
-            raw_mappings = existing_schema.get('mappings', {})
-
+            ## Build up mappings to compare new columns against existing
             mappings = []
 
-            for to, m in raw_mappings.items():
+            for to, m in existing_schema.get('mappings', {}).items():
                 mapping = json_schema.simple_type(m)
                 mapping['from'] = tuple(m['from'])
                 mapping['to'] = to
                 mappings.append(mapping)
 
+            ## Only process columns which have single, nullable, types
+            column_paths_seen = set()
+            single_type_columns = []
+
+            for column_path, column_schema in schema['schema']['properties'].items():
+                column_paths_seen.add(column_path)
+                for sub_schema in column_schema['anyOf']:
+                    single_type_columns.append((column_path, deepcopy(sub_schema)))
+
+            ### Add any columns missing from new schema
+            for m in mappings:
+                if not m['from'] in column_paths_seen:
+                    single_type_columns.append((m['from'], json_schema.make_nullable(m)))
+
+            ## Process new columns against existing
             table_empty = self.is_table_empty(connection, table_name)
 
             for column_path, column_schema in single_type_columns:
diff --git a/tests/unit/test_postgres.py b/tests/unit/test_postgres.py
index 527fefce..1a90c176 100644
--- a/tests/unit/test_postgres.py
+++ b/tests/unit/test_postgres.py
@@ -1059,6 +1059,87 @@ def generate_record(self):
             assert cat_count == len([x for x in persisted_records if x[0] is None])
 
 
+def test_loading__column_type_change__nullable__missing_from_schema(db_cleanup):
+    cat_count = 20
+    main(CONFIG, input_stream=CatStream(cat_count))
+
+    with psycopg2.connect(**TEST_DB) as conn:
+        with conn.cursor() as cur:
+            assert_columns_equal(cur,
+                                 'cats',
+                                 {
+                                     ('_sdc_batched_at', 'timestamp with time zone', 'YES'),
+                                     ('_sdc_received_at', 'timestamp with time zone', 'YES'),
+                                     ('_sdc_sequence', 'bigint', 'YES'),
+                                     ('_sdc_table_version', 'bigint', 'YES'),
+                                     ('adoption__adopted_on', 'timestamp with time zone', 'YES'),
+                                     ('adoption__was_foster', 'boolean', 'YES'),
+                                     ('age', 'bigint', 'YES'),
+                                     ('id', 'bigint', 'NO'),
+                                     ('name', 'text', 'NO'),
+                                     ('bio', 'text', 'NO'),
+                                     ('paw_size', 'bigint', 'NO'),
+                                     ('paw_colour', 'text', 'NO'),
+                                     ('flea_check_complete', 'boolean', 'NO'),
+                                     ('pattern', 'text', 'YES')
+                                 })
+
+            cur.execute(sql.SQL('SELECT {} FROM {}').format(
+                sql.Identifier('name'),
+                sql.Identifier('cats')
+            ))
+            persisted_records = cur.fetchall()
+
+            ## Assert that the original data is present
+            assert cat_count == len(persisted_records)
+            assert cat_count == len([x for x in persisted_records if x[0] is not None])
+
+    class NameMissingCatStream(CatStream):
+        def generate_record(self):
+            record = CatStream.generate_record(self)
+            record['id'] = record['id'] + cat_count
+            del record['name']
+            return record
+
+    stream = NameMissingCatStream(cat_count)
+    stream.schema = deepcopy(stream.schema)
+    del stream.schema['schema']['properties']['name']
+
+    main(CONFIG, input_stream=stream)
+
+    with psycopg2.connect(**TEST_DB) as conn:
+        with conn.cursor() as cur:
+            assert_columns_equal(cur,
+                                 'cats',
+                                 {
+                                     ('_sdc_batched_at', 'timestamp with time zone', 'YES'),
+                                     ('_sdc_received_at', 'timestamp with time zone', 'YES'),
+                                     ('_sdc_sequence', 'bigint', 'YES'),
+                                     ('_sdc_table_version', 'bigint', 'YES'),
+                                     ('adoption__adopted_on', 'timestamp with time zone', 'YES'),
+                                     ('adoption__was_foster', 'boolean', 'YES'),
+                                     ('age', 'bigint', 'YES'),
+                                     ('id', 'bigint', 'NO'),
+                                     ('name', 'text', 'YES'),
+                                     ('bio', 'text', 'NO'),
+                                     ('paw_size', 'bigint', 'NO'),
+                                     ('paw_colour', 'text', 'NO'),
+                                     ('flea_check_complete', 'boolean', 'NO'),
+                                     ('pattern', 'text', 'YES')
+                                 })
+
+            cur.execute(sql.SQL('SELECT {} FROM {}').format(
+                sql.Identifier('name'),
+                sql.Identifier('cats')
+            ))
+            persisted_records = cur.fetchall()
+
+            ## Assert that the column is has migrated data
+            assert 2 * cat_count == len(persisted_records)
+            assert cat_count == len([x for x in persisted_records if x[0] is not None])
+            assert cat_count == len([x for x in persisted_records if x[0] is None])
+
+
 def test_loading__multi_types_columns(db_cleanup):
     stream_count = 50
     main(CONFIG, input_stream=MultiTypeStream(stream_count))