diff --git a/mastodon/polls.py b/mastodon/polls.py
index 20a1d87..013dfe9 100644
--- a/mastodon/polls.py
+++ b/mastodon/polls.py
@@ -56,6 +56,6 @@ class Mastodon(Internals):
         Set multiple to True to allow people to choose more than one answer. Set
         hide_totals to True to hide the results of the poll until it has expired.
         """
-        poll_params = locals()
+        poll_params = locals().copy()
         del poll_params["self"]
         return poll_params