diff --git a/lib/configproxy.js b/lib/configproxy.js
index 8afccd25..f46b6797 100644
--- a/lib/configproxy.js
+++ b/lib/configproxy.js
@@ -510,6 +510,12 @@ class ConfigurableProxy extends EventEmitter {
         return;
       }
 
+      // X-Forwarded-Proto may have multiple values, Tornado uses the last but we want the first
+      if (req.headers['x-forwarded-proto']) {
+        req.headers['x-forwarded-proto'] = req.headers['x-forwarded-proto'].split(',')[0];
+        that.log.debug('Using first x-forwarded-proto: ' + req.headers['x-forwarded-proto'])
+      }
+
       if (kind === "web") {
         that.emit("proxyRequest", req, res);
       }