diff --git a/rules/first-party.list b/rules/first-party.list
index 117d23d..0f35b1f 100644
--- a/rules/first-party.list
+++ b/rules/first-party.list
@@ -83,3 +83,5 @@ ghochv3eng.trafficmanager.net
 thirdparty.bnc.lt
 # Plausible.io
 custom.plausible.io
+# DataUnlocker
+smartproxy.dataunlocker.com
diff --git a/tests/first-party.csv b/tests/first-party.csv
index 8abacd9..7ba21dc 100644
--- a/tests/first-party.csv
+++ b/tests/first-party.csv
@@ -24,3 +24,4 @@ https://www.bouygues-immobilier.com/,,go.bouygues-immobilier.fr,Pardot
 https://caddyserver.com/,,mule.caddysever.com,Fathom
 Reddit.com mail notifications,,click.redditmail.com,Branch.io
 https://www.phpliveregex.com/,,yolo.phpliveregex.xom,Plausible.io
+https://www.earthclassmail.com/,,1avhg3kanx9.www.earthclassmail.com,DataUnlocker