diff --git a/nginx.tmpl b/nginx.tmpl
index 2ad4339..cf4370d 100644
--- a/nginx.tmpl
+++ b/nginx.tmpl
@@ -702,7 +702,17 @@ server {
         return 444;
     }
         {{- end }}
-    return 503;
+
+        {{- if (exists "/usr/share/nginx/html/50x.html") }}
+    error_page 500 502 503 504 /50x.html;
+    location /50x.html {
+        root /usr/share/nginx/html;
+        internal;
+    }
+        {{- end }}
+    location / {
+        return 503;
+    }
 }
     {{- end }}
 {{- end }}
diff --git a/test/test_custom-error-page/50x.html b/test/test_custom-error-page/50x.html
new file mode 100644
index 0000000..63a299e
--- /dev/null
+++ b/test/test_custom-error-page/50x.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>Maintenance</title>
+    <style>
+      html {
+        color-scheme: light dark;
+      }
+      body {
+        width: 35em;
+        margin: 0 auto;
+        font-family: Tahoma, Verdana, Arial, sans-serif;
+      }
+    </style>
+  </head>
+  <body>
+    <h1>Damn, there's some maintenance in progress.</h1>
+    <p>
+      Our apologies for this temporary inconvenience. Regular service
+      performance will be re-established shortly.
+    </p>
+  </body>
+</html>
diff --git a/test/test_custom-error-page/test_custom-error-page.py b/test/test_custom-error-page/test_custom-error-page.py
new file mode 100644
index 0000000..32cb0b5
--- /dev/null
+++ b/test/test_custom-error-page/test_custom-error-page.py
@@ -0,0 +1,8 @@
+import pytest
+import re
+
+
+def test_custom_error_page(docker_compose, nginxproxy):
+    r = nginxproxy.get("http://unknown.nginx-proxy.tld")
+    assert r.status_code == 503
+    assert re.search(r"Damn, there's some maintenance in progress.", r.text)
diff --git a/test/test_custom-error-page/test_custom-error-page.yml b/test/test_custom-error-page/test_custom-error-page.yml
new file mode 100644
index 0000000..8c00e0f
--- /dev/null
+++ b/test/test_custom-error-page/test_custom-error-page.yml
@@ -0,0 +1,8 @@
+version: "2"
+
+services:
+  sut:
+    image: nginxproxy/nginx-proxy:test
+    volumes:
+      - /var/run/docker.sock:/tmp/docker.sock:ro
+      - ./50x.html:/usr/share/nginx/html/50x.html:ro
