diff --git a/Docker/nginx/nginx.conf b/Docker/nginx/nginx.conf
index 302359ecd..fec1b57d6 100644
--- a/Docker/nginx/nginx.conf
+++ b/Docker/nginx/nginx.conf
@@ -122,6 +122,12 @@ server {
     }
 }
 
+# Required by websocket configuration (see mailhog server configuration)
+map $http_upgrade $connection_upgrade {
+    default upgrade;
+    '' close;
+}
+
 upstream mailhog.remp.press {
         server mailhog:8025;
 }
@@ -131,5 +137,13 @@ server {
 
     location / {
         proxy_pass http://mailhog.remp.press;
+
+        # Websocket configuration
+        # See:
+        #  - https://www.nginx.com/blog/websocket-nginx/
+        #  - https://github.com/mailhog/MailHog/issues/117
+        proxy_http_version 1.1;
+        proxy_set_header Upgrade $http_upgrade;
+        proxy_set_header Connection $connection_upgrade;
     }
 }
diff --git a/docker-compose.yml b/docker-compose.yml
index 2dac91a95..f062fb306 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -36,7 +36,7 @@ services:
   mailhog:
     image: "mailhog/mailhog:v1.0.0"
     environment:
-      MH_domainname: "mailhog.remp.press"
+      MH_HOSTNAME: "mailhog.remp.press"
 
   adminer:
     build: "./Docker/php"