diff --git a/src/test/connector.rs b/src/test/connector.rs
index 4e191050d0e0a0f17e89a01308f4d22994df31b7..d89e4546e00a6cd89d7317e65ea9a4e4a1eef6e5 100644
--- a/src/test/connector.rs
+++ b/src/test/connector.rs
@@ -6,6 +6,9 @@ use crate::common::*;
 use crate::runtime::{errors::*, PortBinding::*};
 
 static PDL: &[u8] = b"
+primitive forward_once(in i, out o) {
+    synchronous() put(o, get(i));
+}
 primitive blocked(in i, out o) {
     while(true) synchronous {}
 }