diff --git a/core/Command/User/Info.php b/core/Command/User/Info.php
index de2fd99652c76..8cd481d6b1d5b 100644
--- a/core/Command/User/Info.php
+++ b/core/Command/User/Info.php
@@ -47,6 +47,22 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 			return 1;
 		}
 		$groups = $this->groupManager->getUserGroupIds($user);
+		$firstLogin = $user->getFirstLogin();
+		$lastLogin = $user->getLastLogin();
+		if ($firstLogin < 0) {
+			$firstSeen = 'unknown';
+		} elseif ($firstLogin === 0) {
+			$firstSeen = 'never';
+		} else {
+			$firstSeen = date(\DateTimeInterface::ATOM, $firstLogin); // ISO-8601
+		}
+		if ($lastLogin < 0) {
+			$lastSeen = 'unknown';
+		} elseif ($lastLogin === 0) {
+			$lastSeen = 'never';
+		} else {
+			$lastSeen = date(\DateTimeInterface::ATOM, $lastLogin); // ISO-8601
+		}
 		$data = [
 			'user_id' => $user->getUID(),
 			'display_name' => $user->getDisplayName(),
@@ -56,8 +72,8 @@ protected function execute(InputInterface $input, OutputInterface $output): int
 			'groups' => $groups,
 			'quota' => $user->getQuota(),
 			'storage' => $this->getStorageInfo($user),
-			'first_seen' => date(\DateTimeInterface::ATOM, $user->getFirstLogin()), // ISO-8601
-			'last_seen' => date(\DateTimeInterface::ATOM, $user->getLastLogin()), // ISO-8601
+			'first_seen' => $firstSeen,
+			'last_seen' => $lastSeen,
 			'user_directory' => $user->getHome(),
 			'backend' => $user->getBackendClassName()
 		];
diff --git a/lib/private/User/User.php b/lib/private/User/User.php
index 311f057be545b..3d5c13d44318d 100644
--- a/lib/private/User/User.php
+++ b/lib/private/User/User.php
@@ -228,15 +228,20 @@ public function updateLastLoginTimestamp(): bool {
 		$previousLogin = $this->getLastLogin();
 		$firstLogin = $this->getFirstLogin();
 		$now = time();
-		$firstTimeLogin = $firstLogin === 0;
+		$firstTimeLogin = $previousLogin === 0;
 
 		if ($now - $previousLogin > 60) {
 			$this->lastLogin = $now;
 			$this->config->setUserValue($this->uid, 'login', 'lastLogin', (string)$this->lastLogin);
 		}
 
-		if ($firstTimeLogin) {
-			$this->firstLogin = $now;
+		if ($firstLogin === 0) {
+			if ($firstTimeLogin) {
+				$this->firstLogin = $now;
+			} else {
+				/* Unknown first login, most likely was before upgrade to Nextcloud 31 */
+				$this->firstLogin = -1;
+			}
 			$this->config->setUserValue($this->uid, 'login', 'firstLogin', (string)$this->firstLogin);
 		}
 
diff --git a/lib/public/IUser.php b/lib/public/IUser.php
index f87fd8398e67e..b4808ec045a4d 100644
--- a/lib/public/IUser.php
+++ b/lib/public/IUser.php
@@ -53,7 +53,7 @@ public function setDisplayName($displayName);
 	public function getLastLogin(): int;
 
 	/**
-	 * Returns the timestamp of the user's first login or 0 if the user did never login
+	 * Returns the timestamp of the user's first login, 0 if the user did never login, or -1 if the data is unknown (first login was on an older version)
 	 *
 	 * @since 31.0.0
 	 */