diff --git a/markov.py b/markov.py
index 25b985a..40a9266 100644
--- a/markov.py
+++ b/markov.py
@@ -22,13 +22,15 @@ import os
 import spacy
 
 parser = argparse.ArgumentParser(description='Generate a novel using Markov chains.')
-parser.add_argument('word_file', help='File used for word selection')
-parser.add_argument('pos_file', help='File used to build part-of-speech Markov chain')
+parser.add_argument('word_file', help='file used for word selection')
+parser.add_argument('pos_file', help='file used to build part-of-speech Markov chain')
+parser.add_argument('-s', '--seed', type=int, help='seed for random number generator')
 args = parser.parse_args()
 
 nlp = spacy.load('en_core_web_sm')
 
-seed = 12345
+seed = args.seed or 12345
+
 rng = np.random.default_rng(seed)
 
 words_text = ''