diff --git a/apps/server/src/controllers/ontimeController.ts b/apps/server/src/controllers/ontimeController.ts
index 4cc0f2513..406940d4d 100644
--- a/apps/server/src/controllers/ontimeController.ts
+++ b/apps/server/src/controllers/ontimeController.ts
@@ -207,11 +207,16 @@ export const postSettings = async (req, res) => {
     const settings = DataProvider.getSettings();
     const editorKey = extractPin(req.body?.editorKey, settings.editorKey);
     const operatorKey = extractPin(req.body?.operatorKey, settings.operatorKey);
+    const serverPort = Number(req.body?.serverPort);
+    if (isNaN(serverPort)) {
+      return res.status(400).send(`Invalid value found for server port: ${req.body?.serverPort}`);
+    }
 
-    if (isDocker && req.body?.serverPort) {
+    const hasChangedPort = settings.serverPort !== serverPort;
+
+    if (isDocker && hasChangedPort) {
       return res.status(403).json({ message: 'Can`t change port when running inside docker' });
     }
-    const serverPort = parseInt(req.body?.serverPort ?? settings.serverPort, 10);
 
     let timeFormat = settings.timeFormat;
     if (req.body?.timeFormat === '12' || req.body?.timeFormat === '24') {