diff --git a/uisimulator/win32/Makefile b/uisimulator/win32/Makefile
index 69e4281601..316f44c900 100644
--- a/uisimulator/win32/Makefile
+++ b/uisimulator/win32/Makefile
@@ -110,7 +110,7 @@ COMMONSRCS = io.c stubs.c lcd-common.c sim_icons.c fmradio.c
 
 FIRMSRCS = $(LCDSRSC) id3.c mp3data.c usb.c mpeg.c mp3_playback.c \
 	powermgmt.c power.c sprintf.c buffer.c strtok.c random.c \
-	timefuncs.c
+	timefuncs.c strcasestr.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 \
diff --git a/uisimulator/x11/Makefile b/uisimulator/x11/Makefile
index 9b9afe3618..3055ca99b5 100644
--- a/uisimulator/x11/Makefile
+++ b/uisimulator/x11/Makefile
@@ -122,7 +122,7 @@ COMMONSRCS = io.c stubs.c lcd-common.c sim_icons.c fmradio.c
 
 FIRMSRCS = $(LCDSRSC) id3.c mp3data.c usb.c mpeg.c mp3_playback.c \
 	powermgmt.c power.c sprintf.c buffer.c strtok.c random.c \
-	timefuncs.c panic.c debug.c
+	timefuncs.c panic.c debug.c strcasestr.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 \