diff --git a/nginx.conf b/nginx.conf
index aacb81d901470b29e66ef9e654c00b2356ab0996..5b5653d0bf9f212a694dc46cedeb7eaac1310e11 100644
--- a/nginx.conf
+++ b/nginx.conf
@@ -96,13 +96,15 @@ http {
 
                 proxy_http_version 1.1;
                 proxy_set_header Upgrade $http_upgrade;
-                proxy_set_header Connection "upgrade";
+		# Disabled, if enable we get "Unknown error on OnlyOffice
+                # proxy_set_header Connection "upgrade";
 
                 proxy_set_header Host $http_host;
                 proxy_set_header X-Real-IP $remote_addr;
                 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                 proxy_set_header X-Forwarded-Host $the_host/ds-vpath;
-                proxy_set_header X-Forwarded-Proto $the_scheme;
+		# Manually set to https to avoid "Unknown error" on OnlyOffice
+                proxy_set_header X-Forwarded-Proto "https";
         }
 
         location ~ \.php(?:$|/) {