diff --git a/lib/private/User/User.php b/lib/private/User/User.php
index 72c0d5c1a883b..f5d93dcd680cb 100644
--- a/lib/private/User/User.php
+++ b/lib/private/User/User.php
@@ -199,7 +199,7 @@ public function setSystemEMailAddress(string $mailAddress): void {
 			$this->setPrimaryEMailAddress('');
 		}
 
-		if ($oldMailAddress !== $mailAddress) {
+		if ($oldMailAddress !== strtolower($mailAddress)) {
 			$this->triggerChange('eMailAddress', $mailAddress, $oldMailAddress);
 		}
 	}