diff --git a/src/pynwb/image.py b/src/pynwb/image.py
index f48b3a667..75d2c1fe9 100644
--- a/src/pynwb/image.py
+++ b/src/pynwb/image.py
@@ -150,9 +150,9 @@ def _check_external_file_starting_frame_length(self):
         the number of files in 'external_file'.
         """
         if self.external_file is None:
-            return True 
+            return 
         if get_data_shape(self.external_file) == get_data_shape(self.starting_frame):
-            return True
+            return
 
         return (
             "%s '%s': The number of frame indices in 'starting_frame' should have "
@@ -164,7 +164,7 @@ def _check_external_file_format(self):
         Check that format is 'external' when external_file is specified.
         """
         if self.external_file is None:
-            return 
+            return
         if self.format == "external":
             return