diff --git a/app.js b/app.js
index 17d782fe4d4..ef198584922 100644
--- a/app.js
+++ b/app.js
@@ -26,6 +26,9 @@ function create (env, ctx) {
       }
     });
     if (secureHstsHeader) { // Add HSTS (HTTP Strict Transport Security) header
+
+      const enableCSP = env.secureCsp ? true : false;
+
       console.info('Enabled SECURE_HSTS_HEADER (HTTP Strict Transport Security)');
       const helmet = require('helmet');
       var includeSubDomainsValue = env.secureHstsHeaderIncludeSubdomains;
@@ -37,14 +40,26 @@ function create (env, ctx) {
           , preload: preloadValue
         }
         , frameguard: false
+        , contentSecurityPolicy: enableCSP
       }));
 
-      var secureCspReportOnly = env.secureCspReportOnly;
+      if (enableCSP) {
+        var secureCspReportOnly = env.secureCspReportOnly;
         if (secureCspReportOnly) {
           console.info('Enabled SECURE_CSP (Content Security Policy header). Not enforcing. Report only.');
         } else {
           console.info('Enabled SECURE_CSP (Content Security Policy header). Enforcing.');
         }
+
+        let frameAncestors = ["'self'"];
+
+        for (let i = 0; i <= 8; i++) {
+          let u = env.settings['frameUrl' + i];
+          if (u) {
+            frameAncestors.push(u);
+          }
+        }
+
         app.use(helmet.contentSecurityPolicy({ //TODO make NS work without 'unsafe-inline'
           directives: {
             defaultSrc: ["'self'"]
@@ -54,10 +69,11 @@ function create (env, ctx) {
             , imgSrc: ["'self'", 'data:']
             , objectSrc: ["'none'"] // Restricts <object>, <embed>, and <applet> elements
             , reportUri: '/report-violation'
-            , frameAncestors: ["'none'"]  // Clickjacking protection, using frame-ancestors
             , baseUri: ["'none'"] // Restricts use of the <base> tag
             , formAction: ["'self'"] // Restricts where <form> contents may be submitted
             , connectSrc: ["'self'", "ws:", "wss:", 'https://fonts.googleapis.com/', 'https://fonts.gstatic.com/']
+            , frameSrc: ["'self'"]
+            , frameAncestors: frameAncestors
           }
           , reportOnly: secureCspReportOnly
         }));
@@ -71,7 +87,7 @@ function create (env, ctx) {
           }
           res.status(204).end();
         })
-      
+      }
     }
   } else {
     console.info('Security settings: INSECURE_USE_HTTP=', insecureUseHttp, ', SECURE_HSTS_HEADER=', secureHstsHeader);