diff --git a/src/evolution-loop.test.ts b/src/evolution-loop.test.ts
index 1606393..5e29b74 100644
--- a/src/evolution-loop.test.ts
+++ b/src/evolution-loop.test.ts
@@ -1381,7 +1381,7 @@ describe("evolution loop", () => {
         )
         .replace(AUTOMATION_MODEL_RE, 'model = "custom-model"')
         .replace(AUTOMATION_REASONING_RE, 'reasoning_effort = "medium"')
-        .replace(AUTOMATION_RRULE_RE, 'rrule = "RRULE:FREQ=WEEKLY;BYDAY=FR"') +
+        .replace(AUTOMATION_RRULE_RE, 'rrule = "FREQ=WEEKLY;BYDAY=FR"') +
       '\nnotification_policy = "failed_runs_only"\nexecution_environment = "local"\ntarget = { type = "project", project_id = "saved-project" }\n';
     await Bun.write(automationPath, updated);
     await Bun.write(
@@ -1392,7 +1392,7 @@ describe("evolution loop", () => {
       true
     );
     const reenabled = await enableEvolutionLoop(project);
-    expect(reenabled.config.rrule).toContain("WEEKLY");
+    expect(reenabled.config.rrule).toBe("RRULE:FREQ=WEEKLY;BYDAY=FR");
     const after = Bun.TOML.parse(
       await readFile(automationPath, "utf8")
     ) as Record<string, unknown>;
diff --git a/src/evolution-loop.ts b/src/evolution-loop.ts
index 9f2c06b..6700a59 100644
--- a/src/evolution-loop.ts
+++ b/src/evolution-loop.ts
@@ -671,7 +671,11 @@ async function enableEvolutionLoopScoped(args: {
     );
   }
   if (existingAutomation.exists && !args.rrule && existingAutomation.rrule) {
-    config.rrule = normalizeRrule(existingAutomation.rrule);
+    config.rrule = normalizeRrule(
+      existingAutomation.rrule.startsWith("RRULE:")
+        ? existingAutomation.rrule
+        : `RRULE:${existingAutomation.rrule}`
+    );
   }
   const scaffold = existingAutomation.exists
     ? { path: join(args.homeDir, ".codex", "automations", name) }
@@ -697,7 +701,7 @@ async function enableEvolutionLoopScoped(args: {
       homeDir: args.homeDir,
       name,
       status: "ACTIVE",
-      rrule: config.rrule,
+      rrule: args.rrule ? config.rrule : undefined,
     });
     await appendLoopAudit(args, {
       generatedAt: now,