diff --git a/module_usb_audio/audio.xc b/module_usb_audio/audio.xc
index 5355169f..637a97b9 100755
--- a/module_usb_audio/audio.xc
+++ b/module_usb_audio/audio.xc
@@ -146,7 +146,7 @@ static inline void doI2SClocks(unsigned divide)
 #pragma unsafe arrays
 {unsigned, unsigned} static deliver(chanend c_out, chanend ?c_spd_out, unsigned divide, unsigned curSamFreq, chanend ?c_dig_rx, chanend ?c_adc)
 {
-#if (I2S_CHANS_ADC != 0)
+#if (I2S_CHANS_ADC != 0) || defined(SPDIF)
 	unsigned sample;
 #endif
     unsigned underflow = 0;