diff --git a/redash/query_runner/query_results.py b/redash/query_runner/query_results.py
index b22bac556f..5bc0eed29a 100644
--- a/redash/query_runner/query_results.py
+++ b/redash/query_runner/query_results.py
@@ -1,3 +1,4 @@
+import datetime
 import decimal
 import hashlib
 import logging
@@ -108,6 +109,8 @@ def flatten(value):
         return json_dumps(value)
     elif isinstance(value, decimal.Decimal):
         return float(value)
+    elif isinstance(value, datetime.timedelta):
+        return str(value)
     else:
         return value
 
diff --git a/tests/query_runner/test_query_results.py b/tests/query_runner/test_query_results.py
index 756797492c..1c7ff70cc8 100644
--- a/tests/query_runner/test_query_results.py
+++ b/tests/query_runner/test_query_results.py
@@ -1,3 +1,4 @@
+import datetime
 import decimal
 import sqlite3
 from unittest import TestCase
@@ -108,11 +109,11 @@ def test_creates_table_with_non_ascii_in_column_name(self):
         create_table(connection, table_name, results)
         connection.execute("SELECT 1 FROM query_123")
 
-    def test_creates_table_with_decimal_in_column_value(self):
+    def test_creates_table_with_decimal_and_timedelta_in_column_value(self):
         connection = sqlite3.connect(":memory:")
         results = {
-            "columns": [{"name": "test1"}, {"name": "test2"}],
-            "rows": [{"test1": 1, "test2": decimal.Decimal(2)}],
+            "columns": [{"name": "test1"}, {"name": "test2"}, {"name": "test3"}],
+            "rows": [{"test1": 1, "test2": decimal.Decimal(2), "test3": datetime.timedelta(seconds=3)}],
         }
         table_name = "query_123"
         create_table(connection, table_name, results)