diff --git a/mysql_ch_replicator/db_replicator.py b/mysql_ch_replicator/db_replicator.py
index 4cd22d0..3787a3b 100644
--- a/mysql_ch_replicator/db_replicator.py
+++ b/mysql_ch_replicator/db_replicator.py
@@ -267,7 +267,7 @@ def perform_initial_replication_table(self, table_name):
         while True:
 
             query_start_value = max_primary_key
-            if 'Int' not in primary_key_type:
+            if 'int' not in primary_key_type.lower() and query_start_value is not None:
                 query_start_value = f"'{query_start_value}'"
 
             records = self.mysql_api.get_records(
diff --git a/test_mysql_ch_replicator.py b/test_mysql_ch_replicator.py
index c6fed82..d083340 100644
--- a/test_mysql_ch_replicator.py
+++ b/test_mysql_ch_replicator.py
@@ -8,7 +8,7 @@
 from mysql_ch_replicator import mysql_api
 from mysql_ch_replicator import clickhouse_api
 from mysql_ch_replicator.binlog_replicator import State as BinlogState
-from mysql_ch_replicator.db_replicator import State as DbReplicatorState
+from mysql_ch_replicator.db_replicator import State as DbReplicatorState, DbReplicator
 
 from mysql_ch_replicator.runner import ProcessRunner
 
@@ -704,3 +704,62 @@ def test_json():
 
     assert json.loads(ch.select(TEST_TABLE_NAME, "name='Ivan'")[0]['data'])['c'] == [1, 2, 3]
     assert json.loads(ch.select(TEST_TABLE_NAME, "name='Peter'")[0]['data'])['c'] == [3, 2, 1]
+
+
+def test_string_primary_key(monkeypatch):
+    monkeypatch.setattr(DbReplicator, 'INITIAL_REPLICATION_BATCH_SIZE', 1)
+
+    cfg = config.Settings()
+    cfg.load(CONFIG_FILE)
+
+    mysql = mysql_api.MySQLApi(
+        database=None,
+        mysql_settings=cfg.mysql,
+    )
+
+    ch = clickhouse_api.ClickhouseApi(
+        database=TEST_DB_NAME,
+        clickhouse_settings=cfg.clickhouse,
+    )
+
+    prepare_env(cfg, mysql, ch)
+
+    mysql.execute("SET sql_mode = 'ALLOW_INVALID_DATES';")
+
+    mysql.execute(f'''
+CREATE TABLE {TEST_TABLE_NAME} (
+    `id` char(30) NOT NULL,
+    name varchar(255),
+    PRIMARY KEY (id)
+); 
+    ''')
+
+    mysql.execute(
+        f"INSERT INTO {TEST_TABLE_NAME} (id, name) VALUES " +
+        """('01', 'Ivan');""",
+        commit=True,
+    )
+    mysql.execute(
+        f"INSERT INTO {TEST_TABLE_NAME} (id, name) VALUES " +
+        """('02', 'Peter');""",
+        commit=True,
+    )
+
+    binlog_replicator_runner = BinlogReplicatorRunner()
+    binlog_replicator_runner.run()
+    db_replicator_runner = DbReplicatorRunner(TEST_DB_NAME)
+    db_replicator_runner.run()
+
+    assert_wait(lambda: TEST_DB_NAME in ch.get_databases())
+
+    ch.execute_command(f'USE {TEST_DB_NAME}')
+
+    assert_wait(lambda: TEST_TABLE_NAME in ch.get_tables())
+    assert_wait(lambda: len(ch.select(TEST_TABLE_NAME)) == 2)
+
+    mysql.execute(
+        f"INSERT INTO {TEST_TABLE_NAME} (id, name) VALUES " +
+        """('03', 'Filipp');""",
+        commit=True,
+    )
+    assert_wait(lambda: len(ch.select(TEST_TABLE_NAME)) == 3)