diff -r 27fb1c3c9fbb -r 97b591813c8b src/polygoncache.cpp
--- a/src/polygoncache.cpp	Sun Mar 13 20:26:28 2022 +0200
+++ b/src/polygoncache.cpp	Tue Mar 15 18:52:48 2022 +0200
@@ -16,7 +16,7 @@
  * @param documents Documents to use to resolve subfile references
  * @return vector of GL polygons
  */
-std::vector<gl::Polygon> PolygonCache::getPolygons(DocumentManager* documents)
+const std::vector<gl::Polygon> &PolygonCache::getPolygons(DocumentManager* documents)
 {
 	if (this->needRecache)
 	{