diff --git a/gridded_glm/libexec/_minute_gridder.py b/gridded_glm/libexec/_minute_gridder.py
index 87bdf71f06145a801a0f1f2edec6fc2e7f9eda85..f8a1840f66c791a2ce3e788b6870caa5970d34f0 100644
--- a/gridded_glm/libexec/_minute_gridder.py
+++ b/gridded_glm/libexec/_minute_gridder.py
@@ -330,9 +330,13 @@ if __name__ == '__main__':
         if len(fileglob) != 3:
             log.error("There are not (yet) three GLM files from this minute. This may be expected. Exiting.")
             exit(0)
+
+        # this allows a user to use realtime mode to process a large directory of GLM without
+        # creating the same output file multiple times
         if sorted(fileglob)[-1] != args.filenames[0]:
             log.error("This is not the last file from this minute. Exiting.")
             exit(0)
+
         args.filenames = fileglob
 
     # check that all of our inputs exist