diff --git a/cmd/gadfly/zz_inline_probe.go b/cmd/gadfly/zz_inline_probe.go
new file mode 100644
index 0000000..d8e6e88
--- /dev/null
+++ b/cmd/gadfly/zz_inline_probe.go
@@ -0,0 +1,15 @@
+package main
+
+import "strconv"
+
+// probeParsePort is a THROWAWAY used only to validate Gadfly's inline-review
+// anchoring end-to-end (this branch is never merged). It deliberately ignores
+// the error from Atoi and hardcodes a fallback, so the swarm has a concrete
+// finding to anchor an inline comment to on a changed line.
+func probeParsePort(s string) int {
+	n, _ := strconv.Atoi(s)
+	if n == 0 {
+		return 8080
+	}
+	return n
+}