diff --git a/towncrier/newsfragments/3913.bugfix b/towncrier/newsfragments/3913.bugfix
new file mode 100644
index 00000000..04a07e8c
--- /dev/null
+++ b/towncrier/newsfragments/3913.bugfix
@@ -0,0 +1 @@
+Re-enable nginx buffering as apparently roundcube is broken without
diff --git a/webmails/nginx-webmail.conf b/webmails/nginx-webmail.conf
index 067ee718..6b3edbdf 100644
--- a/webmails/nginx-webmail.conf
+++ b/webmails/nginx-webmail.conf
@@ -60,7 +60,10 @@ server {
         fastcgi_param CONTENT_LENGTH  $content_length;
         fastcgi_param PATH_INFO       $fastcgi_path_info;
 
-        fastcgi_request_buffering off;
+        # unclear why this is required, see #3913
+        fastcgi_buffers 16 32k;
+        fastcgi_buffer_size 64k;
+        fastcgi_busy_buffers_size 64k;
 
         # nginx buffers #
         proxy_buffer_size 128k;