diff --git a/config.example.js b/config.example.js
index 974890cfa..b5ec1717d 100644
--- a/config.example.js
+++ b/config.example.js
@@ -88,6 +88,28 @@ module.exports = {
         "img-src * blob:",
     ].join('; '),
 
+    // OnlyOffice requires even more lax content security policy in order to function.
+    ooContentSecurity: [
+        "default-src 'none'",
+        "style-src 'unsafe-inline' 'self'" + domain,
+        // Unsafe inline, unsafe-eval are needed for ckeditor :(
+        "script-src 'self' 'unsafe-eval' 'unsafe-inline'" + domain,
+        "font-src 'self'" + domain,
+
+        /*  See above under 'contentSecurity' as to how these values should be
+         *  configured for best effect.
+         */
+        "child-src *",
+        // IE/Edge
+        "frame-src *",
+
+        // see the comment above in the 'contentSecurity' section
+         "connect-src 'self' blob: ws: wss:" + domain,
+
+        // (insecure remote) images are included by users of the wysiwyg who embed photos in their pads
+        "img-src * blob: data:",
+    ].join('; '),
+
     httpPort: 3000,
 
     // This is for allowing the cross-domain iframe to function when developing
diff --git a/server.js b/server.js
index 4523ffc67..347140b7c 100644
--- a/server.js
+++ b/server.js
@@ -75,9 +75,20 @@ var setHeaders = (function () {
     if (config.padContentSecurity) {
         padHeaders['Content-Security-Policy'] = clone(config.padContentSecurity);
     }
+    const ooHeaders = clone(headers);
+    if (config.ooContentSecurity) {
+        ooHeaders['Content-Security-Policy'] = clone(config.ooContentSecurity);
+    }
     if (Object.keys(headers).length) {
         return function (req, res) {
-            const h = /^\/pad(2)?\/inner\.html.*/.test(req.url) ? padHeaders : headers;
+            const h = [/^\/pad(2)?\/inner\.html.*/].some((regex) => {
+                    return regex.test(req.url)
+                }) ? padHeaders : ([
+                    /^\/sheet\/inner\.html.*/,
+                    /^\/common\/onlyoffice\/.*\/index\.html.*/
+                ].some((regex) => {
+                return regex.test(req.url)
+            }) ? ooHeaders : headers);
             for (let header in h) { res.setHeader(header, h[header]); }
         };
     }