From cdfcf49d8929d4ba324758cf6caf76dbf9bae95b Mon Sep 17 00:00:00 2001
From: Owen <owen@txv.io>
Date: Thu, 11 Dec 2025 14:20:52 -0500
Subject: [PATCH] Fix host header not working in health checks

---
 healthcheck/healthcheck.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/healthcheck/healthcheck.go b/healthcheck/healthcheck.go
index 46bddea..23ca4bd 100644
--- a/healthcheck/healthcheck.go
+++ b/healthcheck/healthcheck.go
@@ -398,7 +398,12 @@ func (m *Monitor) performHealthCheck(target *Target) {
 
 	// Add headers
 	for key, value := range target.Config.Headers {
-		req.Header.Set(key, value)
+		// Handle Host header specially - it must be set on req.Host, not in headers
+		if strings.EqualFold(key, "Host") {
+			req.Host = value
+		} else {
+			req.Header.Set(key, value)
+		}
 	}
 
 	// Perform request