diff --git a/drivers/ws281x/esp32.c b/drivers/ws281x/esp32.c
index e93f8b6f36..009a709e79 100644
--- a/drivers/ws281x/esp32.c
+++ b/drivers/ws281x/esp32.c
@@ -64,6 +64,7 @@ static uint8_t _rmt_channel(ws281x_t *dev)
         }
     }
     assert(0);
+    return 0;   /* avoid compilation problems with NDEBUG */
 }
 #endif