diff --git a/addons/xterm-addon-webgl/src/renderLayer/BaseRenderLayer.ts b/addons/xterm-addon-webgl/src/renderLayer/BaseRenderLayer.ts
index 2b181847..b897ed44 100644
--- a/addons/xterm-addon-webgl/src/renderLayer/BaseRenderLayer.ts
+++ b/addons/xterm-addon-webgl/src/renderLayer/BaseRenderLayer.ts
@@ -153,7 +153,7 @@ export abstract class BaseRenderLayer implements IRenderLayer {
    * @param x The column to fill.
    * @param y The row to fill.
    */
-  protected _fillLeftLineAtCell(x: number, y: number, width: number = 1): void {
+  protected _fillLeftLineAtCell(x: number, y: number, width: number): void {
     this._ctx.fillRect(
         x * this._scaledCellWidth,
         y * this._scaledCellHeight,
diff --git a/src/browser/renderer/BaseRenderLayer.ts b/src/browser/renderer/BaseRenderLayer.ts
index 2dfe5bd3..4ea8bd52 100644
--- a/src/browser/renderer/BaseRenderLayer.ts
+++ b/src/browser/renderer/BaseRenderLayer.ts
@@ -171,7 +171,7 @@ export abstract class BaseRenderLayer implements IRenderLayer {
    * @param x The column to fill.
    * @param y The row to fill.
    */
-  protected _fillLeftLineAtCell(x: number, y: number, width: number = 1): void {
+  protected _fillLeftLineAtCell(x: number, y: number, width: number): void {
     this._ctx.fillRect(
         x * this._scaledCellWidth,
         y * this._scaledCellHeight,