diff --git a/tensorflow_data_validation/utils/stats_gen_lib.py b/tensorflow_data_validation/utils/stats_gen_lib.py
index af69c254..85730eab 100644
--- a/tensorflow_data_validation/utils/stats_gen_lib.py
+++ b/tensorflow_data_validation/utils/stats_gen_lib.py
@@ -51,7 +51,7 @@
 
 def generate_statistics_from_tfrecord(
     data_location: Text,
-    output_path: Optional[bytes] = None,
+    output_path: Optional[str] = None,
     stats_options: options.StatsOptions = options.StatsOptions(),
     pipeline_options: Optional[PipelineOptions] = None,
 ) -> statistics_pb2.DatasetFeatureStatisticsList:
@@ -111,7 +111,7 @@ def generate_statistics_from_csv(
     data_location: Text,
     column_names: Optional[List[types.FeatureName]] = None,
     delimiter: Text = ',',
-    output_path: Optional[bytes] = None,
+    output_path: Optional[str] = None,
     stats_options: options.StatsOptions = options.StatsOptions(),
     pipeline_options: Optional[PipelineOptions] = None,
     compression_type: Text = CompressionTypes.AUTO,