diff --git a/src/mocks.rs b/src/mocks.rs
index 0e00aad..cb25005 100644
--- a/src/mocks.rs
+++ b/src/mocks.rs
@@ -685,6 +685,7 @@ impl LightningNode for MockNode {
         Ok(AddInvoiceResult {
             pr: format!("lnrt1{}", hex_id),
             payment_hash: hex_id.clone(),
+            external_id: None,
         })
     }