diff --git a/src/svg-quirks-mode/svg-renderer.js b/src/svg-quirks-mode/svg-renderer.js
index 23adc6a..016ce06 100644
--- a/src/svg-quirks-mode/svg-renderer.js
+++ b/src/svg-quirks-mode/svg-renderer.js
@@ -234,11 +234,11 @@ class SvgRenderer {
         // Enlarge the bbox from the largest found stroke width
         // This may have false-positives, but at least the bbox will always
         // contain the full graphic including strokes.
-        const largestStrokeWidth = this._findLargestStrokeWidth(this._svgTag);
-        bbox.width += largestStrokeWidth * 2;
-        bbox.height += largestStrokeWidth * 2;
-        bbox.x -= largestStrokeWidth;
-        bbox.y -= largestStrokeWidth;
+        const halfStrokeWidth = this._findLargestStrokeWidth(this._svgTag) / 2;
+        bbox.width += halfStrokeWidth * 2;
+        bbox.height += halfStrokeWidth * 2;
+        bbox.x -= halfStrokeWidth;
+        bbox.y -= halfStrokeWidth;
 
         // Set the correct measurements on the SVG tag, and save them.
         this._svgTag.setAttribute('width', bbox.width);