diff --git a/certbot/setup.py b/certbot/setup.py
index ef5ffd65e..ecec3a1a4 100644
--- a/certbot/setup.py
+++ b/certbot/setup.py
@@ -46,7 +46,7 @@ install_requires = [
     # 1.1.0+ is required to avoid the warnings described at
     # https://github.com/certbot/josepy/issues/13.
     'josepy>=1.1.0',
-    'parsedatetime>=1.3',  # Calendar.parseDT
+    'parsedatetime>=2.4',
     'pyrfc3339',
     'pytz',
     'setuptools>=39.0.1',
diff --git a/tools/oldest_constraints.txt b/tools/oldest_constraints.txt
index 97b9e3fa3..5aeae7b4e 100644
--- a/tools/oldest_constraints.txt
+++ b/tools/oldest_constraints.txt
@@ -48,7 +48,6 @@ pyparsing==2.2.0
 # Our setup.py constraints
 apacheconfig==0.3.2
 cloudflare==1.5.1
-parsedatetime==1.3
 python-digitalocean==1.11
 requests[security]==2.6.0
 
@@ -71,6 +70,7 @@ setuptools==39.0.1
 
 # Ubuntu Focal constraints
 configobj==5.0.6
+parsedatetime==2.4
 
 # Plugin constraints
 # These aren't necessarily the oldest versions we need to support