diff --git a/src/main.c b/src/main.c
index e56c5aa..a450aeb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -552,7 +552,7 @@ static void rf_rx(void)
 			else if (I < -128)
 				I = -128;
 
-			*blockptr++ = I + 128;
+			*blockptr++ = (uint8_t)I + 128;
 
 			Q *= gain;
 			Q /= max_amplitude;