diff --git a/superset/common/query_object.py b/superset/common/query_object.py
index 4c83c87265f2..b2822e37daca 100644
--- a/superset/common/query_object.py
+++ b/superset/common/query_object.py
@@ -78,9 +78,7 @@ def __init__(
         )
         self.is_timeseries = is_timeseries
         self.time_range = time_range
-        self.time_shift = (
-            utils.parse_human_timedelta(time_shift) if time_shift else None
-        )
+        self.time_shift = utils.parse_human_timedelta(time_shift)
         self.groupby = groupby or []
 
         # Temporal solution for backward compatability issue
diff --git a/superset/utils/core.py b/superset/utils/core.py
index f4d1ac85c13d..a27ff71a0fc4 100644
--- a/superset/utils/core.py
+++ b/superset/utils/core.py
@@ -291,7 +291,7 @@ def default(self, o):
             return json.JSONEncoder(sort_keys=True).default(self, o)
 
 
-def parse_human_timedelta(s: str) -> timedelta:
+def parse_human_timedelta(s: Optional[str]) -> timedelta:
     """
     Returns ``datetime.datetime`` from natural language time deltas
 
diff --git a/tests/utils_tests.py b/tests/utils_tests.py
index ad9fa0d00334..02703f027980 100644
--- a/tests/utils_tests.py
+++ b/tests/utils_tests.py
@@ -130,6 +130,7 @@ def test_parse_human_timedelta(self, mock_datetime):
         self.assertEqual(parse_human_timedelta("now"), timedelta(0))
         self.assertEqual(parse_human_timedelta("1 year"), timedelta(366))
         self.assertEqual(parse_human_timedelta("-1 year"), timedelta(-365))
+        self.assertEqual(parse_human_timedelta(None), timedelta(0))
 
     @patch("superset.utils.core.datetime")
     def test_parse_past_timedelta(self, mock_datetime):