diff --git a/examples/device/cdc_msc/src/main.c b/examples/device/cdc_msc/src/main.c
index 6b13ba5a..a20a80fc 100644
--- a/examples/device/cdc_msc/src/main.c
+++ b/examples/device/cdc_msc/src/main.c
@@ -133,6 +133,7 @@ void cdc_task(void)
 void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts)
 {
   (void) itf;
+  (void) rts;
 
   // connected
   if ( dtr )