diff --git a/src/browser/Decorations/OverviewRulerRenderer.ts b/src/browser/Decorations/OverviewRulerRenderer.ts
index 54862fb0..d6ac4941 100644
--- a/src/browser/Decorations/OverviewRulerRenderer.ts
+++ b/src/browser/Decorations/OverviewRulerRenderer.ts
@@ -74,18 +74,19 @@ export class OverviewRulerRenderer extends Disposable {
     } else {
       this._canvas.style.left = decoration.options.x ? `${decoration.options.x * this._renderService.dimensions.actualCellWidth}px` : '';
     }
-    if (!decoration.options.overviewRulerOptions?.color) {
+    if (!decoration.options.overviewRulerOptions) {
       this._decorationElements.delete(decoration);
       return;
     }
     this._ctx.lineWidth = 1;
     this._ctx.strokeStyle = decoration.options.overviewRulerOptions.color;
-    const size = Math.floor(this._width / 3);
+    const outerSize = Math.floor(this._width / 3);
+    const innerSize = Math.ceil(this._width / 3);
     const position = decoration.options.overviewRulerOptions.position;
     this._ctx.strokeRect(
-      !position ||  position === 'left' ? 0 : position === 'right' ? size * 2 + 1: size,
+      !position ||  position === 'left' ? 0 : position === 'right' ? outerSize + innerSize: outerSize,
       Math.round(this._canvas.height * (decoration.options.marker.line / this._bufferService.buffers.active.lines.length)),
-      !position ? this._canvas.width : position === 'center' ? size + 1 : size,
+      !position ? this._canvas.width : position === 'center' ? innerSize : outerSize,
       window.devicePixelRatio
     );
   }
diff --git a/typings/xterm.d.ts b/typings/xterm.d.ts
index e1c51934..a86d80c8 100644
--- a/typings/xterm.d.ts
+++ b/typings/xterm.d.ts
@@ -432,8 +432,8 @@ declare module 'xterm' {
     readonly onRender: IEvent<HTMLElement>;
 
     /**
-     * The HTMLElement that gets created or drawn to (for scrollbar decorations)
-     * after the first _onRender call, or undefined if accessed before
+     * The element that the decoration is rendered to. This will be undefined
+     * until it is rendered for the first time by @{link IDecoration.onRender}.
      * that.
      */
     element: HTMLElement | undefined;
@@ -465,23 +465,21 @@ declare module 'xterm' {
 
 
     /**
-     * The width of the decoration in cells, which defaults to
-     * cell width or the width in pixels, when an overlayRulerItemColor
-     * is provided.
+     * The width of the decoration in cells, defaults to 1.
      */
     readonly width?: number;
 
     /**
-     * The height of the decoration in cells, which defaults to
-     * cell height
+     * The height of the decoration in cells, defaults to 1.
      */
     readonly height?: number;
 
     /**
-     * Renders the decoration in the scrollbar
-     * with the given @param color and optional @param position.
-     * If @param position is not set, it will span the full @param overviewRulerWidth, which
-     * must be provided via @TerminalOptions for this to work.
+     * When defined, renders the decoration in the overview ruler to the right
+     * of the terminal. {@link ITerminalOptions.overviewRulerWidth} must be set
+     * in order to see the overview ruler.
+     * @param color The color of the decoration.
+     * @param position The position of the decoration.
      */
     readonly overviewRulerOptions?: { color: string; position?: 'left' | 'center' | 'right'}
   }