diff --git a/pyathena/result_set.py b/pyathena/result_set.py
index <HASH>..<HASH> 100644
--- a/pyathena/result_set.py
+++ b/pyathena/result_set.py
@@ -309,6 +309,7 @@ class AthenaPandasResultSet(AthenaResultSet):
         )
         if (
             self.state == AthenaQueryExecution.STATE_SUCCEEDED
+            and self.output_location
             and self.output_location.endswith((".csv", ".txt"))
         ):
             self._df = self._as_pandas()
Fix Item "None" of "Optional[str]" has no attribute "endswith"