diff --git a/source/R/steekproeftrekking_nabehandeling.R b/source/R/steekproeftrekking_nabehandeling.R
index b29e7160..035f9623 100644
--- a/source/R/steekproeftrekking_nabehandeling.R
+++ b/source/R/steekproeftrekking_nabehandeling.R
@@ -68,6 +68,7 @@ replace_by_existing <- function(sample,
                                 gebied,
                                 overlap_prop = 0.5,
                                 sbp_file) {
+  stop(sf::st_crs(existing_points)$input == "EPSG:28992")
   # Determine where HOL and OL is in gebied
   ol <- selectie_openheid(
     gebied = gebied,