diff --git a/src/components/fabric/QPolygon.js b/src/components/fabric/QPolygon.js
index 2005395c..a0852d6c 100644
--- a/src/components/fabric/QPolygon.js
+++ b/src/components/fabric/QPolygon.js
@@ -35,7 +35,7 @@ export const QPolygon = fabric.util.createClass(fabric.Polygon, {
         }
         const nextPoint = points[(i + 1) % points.length]
         const angle = calculateAngle(point, nextPoint)
-        if (!(Math.abs(angle) === 0 || Math.abs(angle) === 180)) {
+        if (!(Math.abs(angle) === 0 || Math.abs(angle) === 180 || Math.abs(angle) === 90)) {
           isDiagonal = true
         }
       })