diff --git a/data/api/client-server/voip.yaml b/data/api/client-server/voip.yaml
index 4466e36c..8c41da21 100644
--- a/data/api/client-server/voip.yaml
+++ b/data/api/client-server/voip.yaml
@@ -44,6 +44,8 @@ paths:
                     type: array
                     items:
                       type: string
+                      format: uri
+                      pattern: "$turns?:"
                     description: A list of TURN URIs
                   ttl:
                     type: integer