diff --git a/src/script_opt/ZAM/OPs/ZBI.op b/src/script_opt/ZAM/OPs/ZBI.op
index ed0e0c58a1..be13f0f082 100644
--- a/src/script_opt/ZAM/OPs/ZBI.op
+++ b/src/script_opt/ZAM/OPs/ZBI.op
@@ -130,7 +130,7 @@ eval	auto cid = $1;
 		res = conn->GetVal();
 	else
 		{
-		ERROR2("connection ID not a known connection", cid);
+		emit_builtin_error("connection ID not a known connection", cid);
 		res = build_dummy_conn_record();
 		}
 	AssignTarget($$, ZVal(res, res->GetType()));
diff --git a/testing/btest/Baseline.zam/bifs.lookup_connection/.stderr b/testing/btest/Baseline.zam/bifs.lookup_connection/.stderr
new file mode 100644
index 0000000000..a3d89ea788
--- /dev/null
+++ b/testing/btest/Baseline.zam/bifs.lookup_connection/.stderr
@@ -0,0 +1,7 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+1362692526.869344 error: invalid connection ID record encountered: the proto field has the "unknown" 65535 value. Did you forget to set it?
+1362692526.869344 error in <no location>: connection ID not a known connection ([orig_h=141.142.228.5, orig_p=59856/tcp, resp_h=192.150.187.43, resp_p=80/tcp, proto=65535])
+1362692526.869344 error: invalid connection ID record encountered: the proto field has the "unknown" 65535 value. Did you forget to set it?
+1362692526.869344 error: invalid connection ID record encountered
+1362692526.869344 error in <no location>: connection ID not a known connection ([orig_h=<uninitialized>, orig_p=<uninitialized>, resp_h=<uninitialized>, resp_p=<uninitialized>, proto=65535])
+1362692526.869344 error: invalid connection ID record encountered