diff --git a/uisimulator/win32/Makefile b/uisimulator/win32/Makefile
index c49fa89a2d..ff04098cc6 100644
--- a/uisimulator/win32/Makefile
+++ b/uisimulator/win32/Makefile
@@ -75,7 +75,7 @@ FIRMSRCS = $(LCDSRSC) power.c sprintf.c id3.c usb.c \
 
 APPS = main.c tree.c menu.c credits.c main_menu.c icons.c language.c \
 	playlist.c wps.c wps-display.c settings.c status.c \
-	screens.c peakmeter.c viewer.c
+	screens.c peakmeter.c viewer.c sleeptimer.c
 
 MENUS = games_menu.c demo_menu.c settings_menu.c sound_menu.c
 
@@ -164,6 +164,9 @@ $(OBJDIR)/main.o: $(APPDIR)/main.c
 $(OBJDIR)/wps.o: $(APPDIR)/wps.c
 	$(CC) $(APPCFLAGS) -c $< -o $@
 
+$(OBJDIR)/sleeptimer.o: $(APPDIR)/sleeptimer.c
+	$(CC) $(APPCFLAGS) -c $< -o $@
+
 $(OBJDIR)/viewer.o: $(APPDIR)/viewer.c
 	$(CC) $(APPCFLAGS) -c $< -o $@