diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7208f72..7a5ec9f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 - Add a service to manage organisation's their scope of operation [OP-3205]
 - datamodel: Allow a location to be within multiple other locations [OP-3205]
 - datafix: set scope of operation for worship administrative units [OP-3626]
+- Clean dev addresses linked to both sites and contact points of mandatarissen [DL-6701]
 ### Deploy notes
 ```
 drc pull scope-of-operation; drc up -d scope-of-operation
@@ -32,7 +33,6 @@ drc restart migrations; drc logs -ft --tail=200 migrations
 - Add URI to resource's organization responses
 - Fix query for organizations report [OP-3636]
 - Bump report-generation-service to most recent version
-- Write migration to harmonize date formats of change events [OP-3559]
 ### Deploy notes
 ```
 drc pull deltanotifier; drc up -d deltanotifier
diff --git a/config/dev-migrations/20250708142100-fix-same-address-linked-to-both-site-and-contact-point.sparql b/config/dev-migrations/20250708142100-fix-same-address-linked-to-both-site-and-contact-point.sparql
new file mode 100644
index 0000000..24d41a3
--- /dev/null
+++ b/config/dev-migrations/20250708142100-fix-same-address-linked-to-both-site-and-contact-point.sparql
@@ -0,0 +1,31 @@
+DELETE {
+  GRAPH ?h {
+    ?site <https://data.vlaanderen.be/ns/organisatie#bestaatUit> ?oldAddressUri .
+  }
+} INSERT {
+  GRAPH ?g {
+    ?newAddressUri a <http://www.w3.org/ns/locn#Address> ;
+      <http://mu.semte.ch/vocabularies/core/uuid> ?newAddressUuid ;
+      ?p ?o .
+  }
+
+  GRAPH ?h {
+    ?site <https://data.vlaanderen.be/ns/organisatie#bestaatUit> ?newAddressUri .
+  }
+} WHERE {
+  GRAPH ?g {
+    ?oldAddressUri a <http://www.w3.org/ns/locn#Address> ;
+      ?p ?o .
+
+    FILTER (?p NOT IN (<http://mu.semte.ch/vocabularies/core/uuid>))
+  }
+
+  ?mandatarisContact <http://www.w3.org/ns/locn#address> ?oldAddressUri .
+
+  GRAPH ?h {
+    ?site <https://data.vlaanderen.be/ns/organisatie#bestaatUit> ?oldAddressUri .
+  }
+
+  BIND(MD5(CONCAT(?oldAddressUri,"OLD_ADDRESS")) AS ?newAddressUuid) .
+  BIND(IRI(CONCAT("http://data.lblod.info/id/adressen/", STR(?newAddressUuid))) AS ?newAddressUri) .
+}