diff --git a/module_usb_audio/warnings.xc b/module_usb_audio/warnings.xc
index e85973a6..5cbab76f 100644
--- a/module_usb_audio/warnings.xc
+++ b/module_usb_audio/warnings.xc
@@ -61,4 +61,13 @@ Warnings relating to configuration defines located in this XC source file rather
 #warning AUDIO_CLASS_FALLBACK not defined, using 0 (i.e. disabled)
 #endif
 
+/* Sanity check on FS channel counts */
+#if (NUM_USB_CHAN_OUT_FS > NUM_USB_CHAN_OUT)
+#error NUM_USB_CHAN_OUT expected to be less than or equal to NUM_USB_CHAN_OUT
+#endif
+
+#if (NUM_USB_CHAN_IN_FS > NUM_USB_CHAN_IN)
+#error NUM_USB_CHAN_IN expected to be less than or equal to NUM_USB_CHAN_IN
+#endif
+