diff --git a/module_usb_audio/audio.xc b/module_usb_audio/audio.xc
index 0b81d2de..5355169f 100755
--- a/module_usb_audio/audio.xc
+++ b/module_usb_audio/audio.xc
@@ -146,7 +146,9 @@ 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)
 	unsigned sample;
+#endif
     unsigned underflow = 0;
 #if NUM_USB_CHAN_OUT > 0
     unsigned samplesOut[NUM_USB_CHAN_OUT];
diff --git a/module_usb_audio/endpoint0/audiorequests.xc b/module_usb_audio/endpoint0/audiorequests.xc
index 0fa6124a..2153c022 100644
--- a/module_usb_audio/endpoint0/audiorequests.xc
+++ b/module_usb_audio/endpoint0/audiorequests.xc
@@ -15,7 +15,6 @@
 #ifdef MIXER
 #include "mixer.h"
 #endif
-#include <print.h>
 
 #define CS_XU_MIXSEL (0x06)
 
@@ -1098,7 +1097,6 @@ int AudioClassRequests_1(XUD_ep ep0_out, XUD_ep ep0_in, USB_SetupPacket_t &sp, c
     unsigned char buffer[1024];
     int unitID;
     int loop = 1;
-    int i_tmp;
 
     /* Inspect request */
     /* Note we could check sp.bmRequestType.Direction if we wanted to be really careful */
diff --git a/module_usb_audio/mixer/mixer.xc b/module_usb_audio/mixer/mixer.xc
index 7e59d2d7..cc92350b 100644
--- a/module_usb_audio/mixer/mixer.xc
+++ b/module_usb_audio/mixer/mixer.xc
@@ -63,8 +63,9 @@ int samples_to_host_inputs[NUM_USB_CHAN_IN];             /* Audio transmitted to
 int samples_to_host_inputs_buff[NUM_USB_CHAN_IN];        /* Audio transmitted to host i.e. dev inputs */
 #endif
 static int samples_to_host_streams[NUM_USB_CHAN_OUT];    /* Audio stream to host from host */
+#if (MAX_MIX_COUNT > 0)
 static int samples_to_host_outputs[NUM_USB_CHAN_OUT];    /* Device outputs */
-
+#endif
 #if 0
 #pragma xta command "add exclusion mixer1_rate_change"
 #pragma xta command "analyse path mixer1_req mixer1_req"
@@ -522,9 +523,9 @@ static void mixer1(chanend c_host, chanend c_mix_ctl, chanend c_mixer2)
     }
 }
 
+#if (MAX_MIX_COUNT > 0)
 static int mixer2_mix2_flag = (DEFAULT_FREQ > 96000);
 
-#if (MAX_MIX_COUNT > 0)
 #pragma unsafe arrays
 static void mixer2(chanend c_mixer1, chanend c_audio)
 {