diff --git a/lib/private/User/User.php b/lib/private/User/User.php
index 5fa1272f95cc8..0b88ed561731f 100644
--- a/lib/private/User/User.php
+++ b/lib/private/User/User.php
@@ -193,7 +193,7 @@ public function setSystemEMailAddress(string $mailAddress): void {
 			$this->setPrimaryEMailAddress('');
 		}
 
-		if ($oldMailAddress !== $mailAddress) {
+		if ($oldMailAddress !== strtolower($mailAddress)) {
 			$this->triggerChange('eMailAddress', $mailAddress, $oldMailAddress);
 		}
 	}