diff --git a/src/middleware/index.js b/src/middleware/index.js
index ea22f285af..d42ef87436 100644
--- a/src/middleware/index.js
+++ b/src/middleware/index.js
@@ -59,6 +59,19 @@ middleware.ensureLoggedIn = (req, res, next) => {
 	setImmediate(next);
 };
 
+middleware.ensureRelativePath = (req, res, next) => {
+	const prefix = nconf.get('relative_path');
+	if (!prefix) {
+		return setImmediate(next);
+	}
+
+	if (!req.path.startsWith(prefix)) {
+		return controllers.helpers.redirect(res, req.path);
+	}
+
+	return next();
+};
+
 Object.assign(middleware, {
 	admin: require('./admin'),
 	...require('./header'),
diff --git a/src/webserver.js b/src/webserver.js
index e75c59eb00..9dae76d496 100644
--- a/src/webserver.js
+++ b/src/webserver.js
@@ -138,6 +138,8 @@ function setupExpressApp(app) {
 		app.use(compression());
 	}
 
+	app.use(middleware.ensureRelativePath);
+
 	app.get(`${relativePath}/ping`, pingController.ping);
 	app.get(`${relativePath}/sping`, pingController.ping);