diff --git a/certbot/certbot/_internal/ocsp.py b/certbot/certbot/_internal/ocsp.py
index c13ff9700..5bbff4490 100644
--- a/certbot/certbot/_internal/ocsp.py
+++ b/certbot/certbot/_internal/ocsp.py
@@ -105,7 +105,7 @@ class RevocationChecker(object):
         """
         Reads OCSP response file and returns producedAt, thisUpdate
         and nextUpdate values in datetime format, or None if an error
-        occures.
+        occurs.
 
         :param str response_file: File path to OCSP response