diff --git a/include/linux/usb/Kbuild b/include/linux/usb/Kbuild
index 51410e0200cf..ed91fb62674b 100644
--- a/include/linux/usb/Kbuild
+++ b/include/linux/usb/Kbuild
@@ -2,6 +2,7 @@ header-y += audio.h
 header-y += cdc.h
 header-y += ch9.h
 header-y += ch11.h
+header-y += functionfs.h
 header-y += gadgetfs.h
 header-y += midi.h
 header-y += g_printer.h