diff --git a/app.c b/app.c
index db74cec..56de75d 100644
--- a/app.c
+++ b/app.c
@@ -74,6 +74,10 @@ int appInit(App *app) {
   Atom wtval = XInternAtom(app->dpy, "_NET_WM_WINDOW_TYPE_TOOLBAR", False);
   if (wt != None && wtval != None)
     XChangeProperty(app->dpy, app->win, wt, XA_ATOM, 32, PropModeReplace, (unsigned char*)&wtval, 1);
+  Atom pm = XInternAtom(app->dpy, "_HILDON_PORTRAIT_MODE_SUPPORT", False);
+  unsigned int pmval = 1;
+  if (pm)
+    XChangeProperty(app->dpy, app->win, pm, XA_CARDINAL, 32, PropModeReplace, (unsigned char*)&pmval, 1);
   #endif
   #endif