diff --git a/derp/derphttp/derphttp_client.go b/derp/derphttp/derphttp_client.go
index edaa67a3d..efe88c2b3 100644
--- a/derp/derphttp/derphttp_client.go
+++ b/derp/derphttp/derphttp_client.go
@@ -795,7 +795,7 @@ func (c *Client) dialNodeUsingProxy(ctx context.Context, n *tailcfg.DERPNode, pr
 		authHeader = fmt.Sprintf("Proxy-Authorization: %s\r\n", v)
 	}
 
-	if _, err := fmt.Fprintf(proxyConn, "CONNECT %s HTTP/1.1\r\nHost: %s\r\n%s\r\n", target, pu.Hostname(), authHeader); err != nil {
+	if _, err := fmt.Fprintf(proxyConn, "CONNECT %s HTTP/1.1\r\nHost: %s\r\n%s\r\n", target, target, authHeader); err != nil {
 		if ctx.Err() != nil {
 			return nil, ctx.Err()
 		}