diff --git a/src/backend/rest.ts b/src/backend/rest.ts
index ba1ddd58..74e641de 100644
--- a/src/backend/rest.ts
+++ b/src/backend/rest.ts
@@ -199,6 +199,9 @@ export default class RestApiBackend implements Backend {
         'The data source specified the Checkmk Raw Edition, but a Checkmk commercial edition was detected. Some functionality may not be available. Choose commercial editions in the data source settings to enable all features.'
       );
     }
+    if (result.data.edition === 'cse') {
+      throw new Error('Detected Checkmk Cloud (SaaS). Can not query data from Checkmk Cloud (SaaS).');
+    }
     // The REST API would be ok with other users, but the autocompleter are not
     if (!(await this.isAutomationUser(this.datasource.getUsername()))) {
       throw new Error('This data source must authenticate against Checkmk using an automation user.');
@@ -255,6 +258,10 @@ export default class RestApiBackend implements Backend {
 
     // check for cloud edition header
     const checkmkEdition = result.headers.get('X-Checkmk-Edition');
+    // CSE is never supported
+    if (checkmkEdition === 'cse') {
+      throw new Error('Cannot query data from Checkmk Cloud (SaaS).');
+    }
     const allowedEditions = new Set(['cce', 'cme']);
     if (process.env.BUILD_EDITION === 'CLOUD' && !allowedEditions.has(checkmkEdition || '')) {
       throw new Error(