diff --git a/clickhouse_driver/columns/base.py b/clickhouse_driver/columns/base.py
index fba3fd2e..cd1062a5 100644
--- a/clickhouse_driver/columns/base.py
+++ b/clickhouse_driver/columns/base.py
@@ -117,7 +117,7 @@ def prepare_items(self, items):
 
         nulls_map = [False] * len(items) if self.nullable else None
         for i, x in enumerate(items):
-            if x is None:
+            if x is None or x == '':
                 if nullable:
                     nulls_map[i] = True
                     x = null_value