diff --git a/os/emscripten/pre.js b/os/emscripten/pre.js
index 31858b1894..c242e13fd0 100644
--- a/os/emscripten/pre.js
+++ b/os/emscripten/pre.js
@@ -1,4 +1,4 @@
-Module.arguments.push('-mnull', '-snull', '-vsdl:relative_mode');
+Module.arguments.push('-mnull', '-snull', '-vsdl');
 Module['websocket'] = { url: function(host, port, proto) {
     /* openttd.org hosts a WebSocket proxy for the content service. */
     if (host == "content.openttd.org" && port == 3978 && proto == "tcp") {