diff --git a/superset/datasets/schemas.py b/superset/datasets/schemas.py
index 2d471781e05..f248fc70ff3 100644
--- a/superset/datasets/schemas.py
+++ b/superset/datasets/schemas.py
@@ -78,7 +78,7 @@ class DatasetMetricsPutSchema(Schema):
 
 class DatasetPostSchema(Schema):
     database = fields.Integer(required=True)
-    schema = fields.String(validate=Length(0, 250))
+    schema = fields.String(allow_none=True, validate=Length(0, 250))
     table_name = fields.String(required=True, allow_none=False, validate=Length(1, 250))
     sql = fields.String(allow_none=True)
     owners = fields.List(fields.Integer())
@@ -236,7 +236,9 @@ class GetOrCreateDatasetSchema(Schema):
         required=True, metadata={"description": "ID of database table belongs to"}
     )
     schema = fields.String(
-        metadata={"description": "The schema the table belongs to"}, allow_none=True
+        allow_none=True,
+        validate=Length(0, 250),
+        metadata={"description": "The schema the table belongs to"},
     )
     template_params = fields.String(
         metadata={"description": "Template params for the table"}
diff --git a/tests/integration_tests/datasets/api_tests.py b/tests/integration_tests/datasets/api_tests.py
index f87bafcd376..2c358d71140 100644
--- a/tests/integration_tests/datasets/api_tests.py
+++ b/tests/integration_tests/datasets/api_tests.py
@@ -530,7 +530,7 @@ class TestDatasetApi(SupersetTestCase):
         self.login(username="admin")
         table_data = {
             "database": main_db.id,
-            "schema": "",
+            "schema": None,
             "table_name": "ab_permission",
         }
         uri = "api/v1/dataset/"