diff --git a/controllers/excalidraw.php b/controllers/excalidraw.php
index f6758d96746a2883cfe9b9fc46c202ebcd25085a..0b18ab2c97fece97648e3d01c30ae1c9db76ee1e 100755
--- a/controllers/excalidraw.php
+++ b/controllers/excalidraw.php
@@ -11,18 +11,34 @@ class ExcalidrawController extends PluginController
         // The base of the URL is statically configured when building the app.
         // But we are building a plugin for Stud.IP which will be built once and run at many
         // different universities. So the question is, what can we do?
-        // We must provide a base URL, so we provide the base URL '.' (the path of the current page).
+        // We provide CRA with the base URL '.', causing our app to use relative paths for resources.
+        // Then, we use before_filter to redirect the requests it makes to the correct URLs.
+        // There are two cases to handle:
+
+        // Case 1: The action which displays Excalidraw has been requested with an argument.
         // This causes our app to make requests for resources which look like this:
         // https://<studip-base-url>/plugins.php/excalidrawplugin/<current controller>/<current action>/static/media/<filename>.excalidrawlib
-        // We want them to look like this:
+
+        // Case 2: The action which displays Excalidraw has been requested without an argument.
+        // The requests our app makes will look slightly different:
+        // https://<studip-base-url>/plugins.php/excalidrawplugin/<current controller>/static/media/<filename>.excalidrawlib
+
+        // In both cases, we want to redirect the requests to the following URL:
         // https://<studip-base-url>/plugins_packages/UOL/ExcalidrawPlugin/excalidraw-selfhosted/build/static/media/<filename>.excalidrawlib
-        // We provide a 302 redirect to the appropriate url.
-        if (count($args) === 3 && $args[0] === 'static' && $args[1] === 'media' && str_ends_with(
-                $_SERVER['REQUEST_URI'],
-                'excalidrawlib'
-            )) {
-            $url = $this->plugin->getPluginUrl(
-                ) . '/excalidraw-selfhosted/build/static/media/' . $args[2] . '.excalidrawlib';
+
+        $isCase1 = count($args) === 3 && $args[0] === 'static' && $args[1] === 'media' &&
+            str_ends_with($_SERVER['REQUEST_URI'], 'excalidrawlib');
+        $isCase2 = $action === 'static' && count($args) === 2 && $args[0] === 'media' &&
+            str_ends_with($_SERVER['REQUEST_URI'], 'excalidrawlib');
+        if ($isCase1) {
+            $url = $this->plugin->getPluginUrl() . '/excalidraw-selfhosted/build/static/media/' .
+                $args[2] . '.excalidrawlib';
+            $this->redirect($url);
+            return;
+        }
+        if ($isCase2) {
+            $url = $this->plugin->getPluginUrl() . '/excalidraw-selfhosted/build/static/media/' .
+                $args[1] . '.excalidrawlib';
             $this->redirect($url);
             return;
         }