diff --git a/server/app.js b/server/app.js
index 4ee54a3..edeaebc 100644
--- a/server/app.js
+++ b/server/app.js
@@ -50,7 +50,7 @@ function createApp({ skipRateLimits = false } = {}) {
           baseUri: ["'self'"],
           frameAncestors: ["'none'"],
           formAction: ["'self'"],
-          upgradeInsecureRequests: process.env.NODE_ENV === 'production' ? [] : null
+          upgradeInsecureRequests: process.env.TRUST_PROXY ? [] : null
         }
       },
       hsts: { maxAge: 31536000, includeSubDomains: true, preload: true },