diff --git a/ss/SSMain.cc b/ss/SSMain.cc
index 7637736..b6796d2 100644
--- a/ss/SSMain.cc
+++ b/ss/SSMain.cc
@@ -22,6 +22,7 @@
 
 /* switch to the next screensaver mode after this many milliseconds */
 #define SSMODE_TIMEOUT_MSEC (1000*45)
+#define SCREENSAVER_MAX_RUNTIME (30*60*1000)
 
 static SDL_Event event;
 
@@ -86,6 +87,10 @@ void SSMain::run()
     while (SDL_WaitEvent(&event))
     {
         elapsed_msec = SDL_GetTicks();  /* get the time the event occurred at */
+#if SCREENSAVER_MAX_RUNTIME > 0
+        if (elapsed_msec >= SCREENSAVER_MAX_RUNTIME)
+            goto RET;
+#endif
         if (elapsed_msec - lastChanged_msec > SSMODE_TIMEOUT_MSEC)
         {
             delete m_mode;