diff --git a/src/tasks/tidy.ts b/src/tasks/tidy.ts
index 6c4d5b8b..2c08166e 100644
--- a/src/tasks/tidy.ts
+++ b/src/tasks/tidy.ts
@@ -193,7 +193,7 @@ export async function tidyMilestones(api: Api, projects: Project[]): Promise<voi
       }
     });
 
-    if (missingMilestones.length > 0) {
+    if (missingMilestones.length > 0 && !project.archived) {
       await asyncPool(CONCURRENCY, missingMilestones, async (milestone) => {
         await api.createMilestone(project.id, milestone);
         Logger.log(`Created milestone '${milestone}' for project ${project.name_with_namespace}'.`);