diff --git a/packages/backend/src/graphql/schema.graphql b/packages/backend/src/graphql/schema.graphql
index e46b85c0f7..5de35ef09c 100644
--- a/packages/backend/src/graphql/schema.graphql
+++ b/packages/backend/src/graphql/schema.graphql
@@ -620,7 +620,7 @@ type Peer implements Model {
   "Peering connection details"
   http: Http!
   "Incoming tokens"
-  incomingTokens: [String!]
+  incomingTokens: [String!]!
   "Asset of peering relationship"
   asset: Asset!
   "Peer's ILP address"