diff --git a/exercises/gigasecond/gigasecond.py b/exercises/gigasecond/gigasecond.py
index 66d9978609..68c71a6cf5 100644
--- a/exercises/gigasecond/gigasecond.py
+++ b/exercises/gigasecond/gigasecond.py
@@ -1,2 +1,2 @@
-def add_gigasecond():
+def add_gigasecond(birth_date):
     pass