diff --git a/minbpe/base.py b/minbpe/base.py
index a0c3131d..65cc45cf 100644
--- a/minbpe/base.py
+++ b/minbpe/base.py
@@ -105,7 +105,7 @@ def save(self, file_prefix):
         model_file = file_prefix + ".model"
         with open(model_file, 'w') as f:
             # write the version, pattern and merges, that's all that's needed
-            f.write(f"minbpe v1\n")
+            f.write("minbpe v1\n")
             f.write(f"{self.pattern}\n")
             # write the special tokens, first the number of them, then each one
             f.write(f"{len(self.special_tokens)}\n")
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 00000000..c46ba631
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,2 @@
+regex
+tiktoken
\ No newline at end of file