diff --git a/230101/setup.sh b/230101/setup.sh
index 415023f..0697088 100755
--- a/230101/setup.sh
+++ b/230101/setup.sh
@@ -14,7 +14,7 @@ function render_clip() {
 		-filter_complex "
 			gradients=s=1920x1080:c0=$c0:c1=$c1:d=4:x0=480:y0=540:x1=1440:y1=540,
 			format=nv12,hwupload[v];
-			aevalsrc=sin($freq*2*PI*t):s=48000[a]
+			aevalsrc=sin($freq*2*PI*t):s=48000,pan=stereo|c0=c0|c1=c0[a]
 		" \
 		-map "[v]" -map "[a]" \
 		-c:v h264_vaapi -r 25 -t 4 \