diff --git a/lib/hterm.js b/lib/hterm.js
index e80f45a8..66480135 100644
--- a/lib/hterm.js
+++ b/lib/hterm.js
@@ -148,6 +148,7 @@ hterm.Terminal.prototype.setFontSize = function (px) {
     .unicode-node {
       display: inline-block;
       vertical-align: top;
+      width: ${this.scrollPort_.characterSize.width}px;
     }
   `;
 };