diff --git a/setup/extensions.json b/setup/extensions.json
index 6f3e7d9c0e..63ddf5e8f4 100644
--- a/setup/extensions.json
+++ b/setup/extensions.json
@@ -201,13 +201,13 @@
     },
     {
         "name": "libusb",
-        "only": "osx linux",
+        "only": "osx linux haiku",
         "sources": "calibre/devices/libusb/libusb.c",
         "libraries": "usb-1.0"
     },
     {
         "name": "libmtp",
-        "only": "osx linux",
+        "only": "osx linux haiku",
         "sources": "calibre/devices/mtp/unix/devices.c calibre/devices/mtp/unix/libmtp.c",
         "headers": "calibre/devices/mtp/unix/devices.h calibre/devices/mtp/unix/upstream/music-players.h calibre/devices/mtp/unix/upstream/device-flags.h",
         "libraries": "mtp"