diff --git a/home-manager/modules/emacs/config.org b/home-manager/modules/emacs/config.org
index 80add1b..096691e 100644
--- a/home-manager/modules/emacs/config.org
+++ b/home-manager/modules/emacs/config.org
@@ -1702,6 +1702,17 @@ Configure eglot to use the Gleam LSP server
                  '(gleam-ts-mode . ("gleam" "lsp"))))
 #+end_src
 
+*** PlantUML
+
+[[https://plantuml.com][PlantUML]] is a tool to generate a wide variety of diagrams, like sequence, usecase and class diagrams.
+
+#+begin_src emacs-lisp
+  (use-package plantuml-mode
+    :config
+    (setq plantuml-default-exec-mode 'server
+          plantuml-server-url "http://localhost:5080/plantuml"))
+#+end_src
+
 * Org
 
 ** Main org setup
@@ -1768,6 +1779,8 @@ Configuration
 #+name: org-config
 #+begin_src emacs-lisp :tangle no
   (add-to-list 'auto-mode-alist '("\\.org\\'" . org-mode))
+  (add-to-list
+   'org-src-lang-modes '("plantuml" . plantuml))
   (dolist (face '((org-level-1 . 1.2)
                   (org-level-2 . 1.1)
                   (org-level-3 . 1.05)
diff --git a/machines/loki/configuration.nix b/machines/loki/configuration.nix
index 27e9d40..de8f3c6 100644
--- a/machines/loki/configuration.nix
+++ b/machines/loki/configuration.nix
@@ -443,6 +443,11 @@
       # user = "erwin";
       openFirewall = true;
     };
+
+    plantuml-server = {
+      enable = true;
+      listenPort = 5080;
+    };
   };
 
   programs = {