diff --git a/enrich-institutes.ini b/enrich-institutes.ini
index e5307be..dd04c73 100644
--- a/enrich-institutes.ini
+++ b/enrich-institutes.ini
@@ -16,7 +16,7 @@
 
 [assign]
 path = ws.rnsr_id
-value = get("ws.rnsr").map(structs => Array.isArray(structs) ? structs.map(struct => struct.num_nat_struct) : "n/a").filter((id) => id !== "n/a").flatten()
+value = get("ws.rnsr").map(structs => Array.isArray(structs) ? structs.map(struct => struct.num_nat_struct) : "n/a").filter((id) => id !== "n/a").flatten().uniq()
 
 [assign]
 path = ws.instituts