diff --git a/config/reasoner/dl2op/private-info/mapping.n3 b/config/reasoner/dl2op/private-info/mapping.n3
index c4109911..b174238f 100644
--- a/config/reasoner/dl2op/private-info/mapping.n3
+++ b/config/reasoner/dl2op/private-info/mapping.n3
@@ -17,6 +17,7 @@ PREFIX persoon_loket: <http://data.vlaanderen.be/ns/persoon#>
 PREFIX skos:<http://www.w3.org/2004/02/skos/core#>
 PREFIX string: <http://www.w3.org/2000/10/swap/string#>
 PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
+PREFIX ch: <http://data.lblod.info/vocabularies/contacthub/>
 
 
 # DL and OP both use persoon:gebruikteVoornaam but with different semantics (!)