diff --git a/src/ftdi.c b/src/ftdi.c
index c417f70..2c80b73 100644
--- a/src/ftdi.c
+++ b/src/ftdi.c
@@ -969,6 +969,9 @@ int ftdi_write_data(struct ftdi_context *ftdi, unsigned char *buf, int size)
 }
 
 #ifdef LIBFTDI_LINUX_ASYNC_MODE
+#ifdef USB_CLASS_PTP
+#error LIBFTDI_LINUX_ASYNC_MODE is not compatible with libusb-compat-0.1!
+#endif
 /* this is strongly dependent on libusb using the same struct layout. If libusb
    changes in some later version this may break horribly (this is for libusb 0.1.12) */
 struct usb_dev_handle