diff --git a/packages/core/pianoroll.mjs b/packages/core/pianoroll.mjs
index 2c16eb7d0..2c4837432 100644
--- a/packages/core/pianoroll.mjs
+++ b/packages/core/pianoroll.mjs
@@ -198,6 +198,8 @@ export function pianoroll({
   let from = -cycles * playhead;
   let to = cycles * (1 - playhead);
 
+  ctx.lineWidth = 1;
+
   if (timeframeProp) {
     console.warn('timeframe is deprecated! use from/to instead');
     from = 0;