diff --git a/src/util/qpolygon-utils.js b/src/util/qpolygon-utils.js
index 65cbc96d..a574c393 100644
--- a/src/util/qpolygon-utils.js
+++ b/src/util/qpolygon-utils.js
@@ -1380,22 +1380,27 @@ export const splitPolygonWithLines = (polygon) => {
   })
 }
 
-const removeDuplicatePolygons = (polygons) => {
+function normalizePoint(point) {
+  return {
+    x: Math.round(point.x),
+    y: Math.round(point.y),
+  }
+}
+
+function arePolygonsEqual(polygon1, polygon2) {
+  if (polygon1.length !== polygon2.length) return false
+
+  const normalizedPolygon1 = polygon1.map(normalizePoint).sort((a, b) => a.x - b.x || a.y - b.y)
+  const normalizedPolygon2 = polygon2.map(normalizePoint).sort((a, b) => a.x - b.x || a.y - b.y)
+
+  return normalizedPolygon1.every((point, index) => arePointsEqual(point, normalizedPolygon2[index]))
+}
+
+function removeDuplicatePolygons(polygons) {
   const uniquePolygons = []
 
   polygons.forEach((polygon) => {
-    const sortedPolygon = polygon
-      .map((point) => `${Math.floor(point.x)},${Math.floor(point.y)}`)
-      .sort()
-      .join('|')
-    const isDuplicate = uniquePolygons.some((uniquePolygon) => {
-      const sortedUniquePolygon = uniquePolygon
-        .map((point) => `${Math.floor(point.x)},${Math.floor(point.y)}`)
-        .sort()
-        .join('|')
-      return sortedPolygon === sortedUniquePolygon
-    })
-
+    const isDuplicate = uniquePolygons.some((uniquePolygon) => arePolygonsEqual(polygon, uniquePolygon))
     if (!isDuplicate) {
       uniquePolygons.push(polygon)
     }
@@ -3551,7 +3556,7 @@ function createRoofPaddingPolygon(polygon, lines, arcSegments = 0) {
 }
 
 function arePointsEqual(point1, point2) {
-  return Math.abs(point1.x - point2.x) < 1 && Math.abs(point1.y - point2.y) - 1
+  return Math.abs(point1.x - point2.x) <= 1 && Math.abs(point1.y - point2.y) <= 1
 }
 
 function arraysHaveSamePoints(array1, array2) {