diff --git a/targets/mega65/configdb.c b/targets/mega65/configdb.c
index 763779dd..e3efd338 100644
--- a/targets/mega65/configdb.c
+++ b/targets/mega65/configdb.c
@@ -111,6 +111,7 @@ static const struct xemutools_configdef_switch_st switch_options[] = {
 	{ "curskeyjoy", "Cursor keys as joystick [makes your emulator unsable to move cursor in BASIC/etc!]", &hid_joy_on_cursor_keys },
 	{ "showscanlines", "Show scanlines in V200 modes", &configdb.show_scanlines },
 	{ "allowscanlines", "Allow user programs to control scanline visibility", &configdb.allow_scanlines },
+	{ "fastboot", "Try to use sleepless emulation mode during booting", &configdb.fastboot },
 	{ NULL }
 };
 
diff --git a/targets/mega65/configdb.h b/targets/mega65/configdb.h
index ed0d58f1..415d8f4b 100644
--- a/targets/mega65/configdb.h
+++ b/targets/mega65/configdb.h
@@ -108,6 +108,7 @@ struct configdb_st {
 	int	noopl3;
 	int	sidmask;
 	int	audiobuffersize;
+	int	fastboot;
 };
 
 extern struct configdb_st configdb;
diff --git a/targets/mega65/hypervisor.c b/targets/mega65/hypervisor.c
index bde1d4a1..aa2a96e6 100644
--- a/targets/mega65/hypervisor.c
+++ b/targets/mega65/hypervisor.c
@@ -288,6 +288,7 @@ static inline void first_leave ( void )
 	vic4_set_videostd(configdb.videostd, "in hypervisor.c, requested as boot/reset default");
 	// OK, that's enough
 	hdos_notify_system_start_end();
+	xemu_sleepless_temporary_mode(0);	// turn off temporary sleepless mode which may have been enabled before
 	DEBUGPRINT("HYPERVISOR: first return after RESET, end of processing workarounds." NL);
 }
 
diff --git a/targets/mega65/mega65.c b/targets/mega65/mega65.c
index 5556535d..b56a8ece 100644
--- a/targets/mega65/mega65.c
+++ b/targets/mega65/mega65.c
@@ -830,6 +830,7 @@ int main ( int argc, char **argv )
 		configdb.umon = XUMON_DEFAULT_PORT;
 	xumon_init(configdb.umon);
 #endif
+	xemu_sleepless_temporary_mode(configdb.fastboot);
 	if (configdb.prg) {
 		inject_register_prg(configdb.prg, configdb.prgmode);
 	} else {
diff --git a/xemu/emutools.c b/xemu/emutools.c
index 425e512f..3378935b 100644
--- a/xemu/emutools.c
+++ b/xemu/emutools.c
@@ -1236,6 +1236,26 @@ void xemu_timekeeping_start ( void )
 }
 
 
+void xemu_sleepless_temporary_mode ( const int enable )
+{
+	static int enabled = 0;
+	if ((enable && enabled) || (!enable && !enabled))
+		return;
+	enabled = enable;
+	static int sleepless_old = 0;
+	if (enable) {
+		DEBUGPRINT("TIMING: enabling temporary sleepless mode: %s" NL, emu_is_sleepless ? "already sleepless" : "OK");
+		sleepless_old = emu_is_sleepless;
+		emu_is_sleepless = 1;
+	} else {
+		DEBUGPRINT("TIMING: disabling temporary sleepless mode: %s" NL, sleepless_old ? "constant sleepless" : "OK");
+		emu_is_sleepless = sleepless_old;
+		if (!emu_is_sleepless)
+			xemu_timekeeping_start();
+	}
+}
+
+
 void xemu_render_dummy_frame ( Uint32 colour, int texture_x_size, int texture_y_size )
 {
 	int tail;
diff --git a/xemu/emutools.h b/xemu/emutools.h
index 15f534ac..845e7211 100644
--- a/xemu/emutools.h
+++ b/xemu/emutools.h
@@ -209,6 +209,7 @@ extern int xemu_post_init (
 );
 extern int xemu_set_icon_from_xpm ( char *xpm[] );
 extern void xemu_timekeeping_start ( void );
+extern void xemu_sleepless_temporary_mode ( const int enable );
 extern void xemu_render_dummy_frame ( Uint32 colour, int texture_x_size, int texture_y_size );
 extern Uint32 *xemu_start_pixel_buffer_access ( int *texture_tail );
 extern void xemu_update_screen ( void );