diff --git a/providers/class-two-factor-fido-u2f.php b/providers/class-two-factor-fido-u2f.php
index d5ea9a8b..f24e55e2 100644
--- a/providers/class-two-factor-fido-u2f.php
+++ b/providers/class-two-factor-fido-u2f.php
@@ -398,7 +398,7 @@ public static function uninstall_user_meta_keys() {
 		return array(
 			self::REGISTERED_KEY_USER_META_KEY,
 			self::AUTH_DATA_USER_META_KEY,
-			Two_Factor_FIDO_U2F_Admin::REGISTER_DATA_USER_META_KEY,
+			'_two_factor_fido_u2f_register_request', // From Two_Factor_FIDO_U2F_Admin which is not loaded during uninstall.
 		);
 	}
 }
diff --git a/providers/class-two-factor-provider.php b/providers/class-two-factor-provider.php
index 68610c69..0e82dd67 100644
--- a/providers/class-two-factor-provider.php
+++ b/providers/class-two-factor-provider.php
@@ -178,6 +178,8 @@ public static function uninstall_user_meta_keys() {
 	/**
 	 * Return the option keys that need to be deleted on plugin uninstall.
 	 *
+	 * Note: this method doesn't have access to the instantiated provider object.
+	 *
 	 * @return array
 	 */
 	public static function uninstall_options() {