diff --git a/misc/buildbot.sh b/misc/buildbot.sh
index 0e200e8d5..4e407d323 100644
--- a/misc/buildbot.sh
+++ b/misc/buildbot.sh
@@ -77,7 +77,7 @@ build_osx64() {
 build_web()  {
   echo "Building web.."
   rm cc.js
-  $EMSCRIPTEN_PATH *.c -O1 -o cc.js -s FETCH=1 -s WASM=0 -s ALLOW_MEMORY_GROWTH=1 --preload-file texpacks/default.zip -w
+  $EMSCRIPTEN_PATH *.c -O1 -o cc.js -s FETCH=1 -s WASM=0 -s LEGACY_VM_SUPPORT=1 -s ALLOW_MEMORY_GROWTH=1 --preload-file texpacks/default.zip -w
   # so game loads textures from classicube.net/static/default.zip
   sed -i 's#cc.data#/static/default.zip#g' cc.js
   # fix texture pack overlay always showing 'Download size: Determining..."