diff --git a/apps/desktop/src/app/cron/cron-job-model.test.ts b/apps/desktop/src/app/cron/cron-job-model.test.ts
index 97af7ac7b9..839a722cfb 100644
--- a/apps/desktop/src/app/cron/cron-job-model.test.ts
+++ b/apps/desktop/src/app/cron/cron-job-model.test.ts
@@ -2,14 +2,27 @@ import { describe, expect, it } from 'vitest'
 
 import {
   cronEditorUpdates,
+  cronModelChoiceValue,
   jobIsScriptOnly,
   lastErrorSummary,
   parseCronDeliveryTargets,
+  parseCronModelChoiceValue,
   toggleCronDeliveryTarget,
   validateCronEditor
 } from './cron-job-model'
 import { nextRunOverdueMs } from './job-state'
 
+describe('cron model choice values', () => {
+  it('round-trips provider and model colons without ambiguous pairs', () => {
+    const customProvider = cronModelChoiceValue('custom:internlm', 'intern-latest')
+    const colonModel = cronModelChoiceValue('custom', 'internlm:intern-latest')
+
+    expect(customProvider).not.toBe(colonModel)
+    expect(parseCronModelChoiceValue(customProvider)).toEqual({ provider: 'custom:internlm', model: 'intern-latest' })
+    expect(parseCronModelChoiceValue(colonModel)).toEqual({ provider: 'custom', model: 'internlm:intern-latest' })
+  })
+})
+
 describe('jobIsScriptOnly', () => {
   it('is true when no_agent is set and a script is present', () => {
     expect(jobIsScriptOnly({ no_agent: true, script: 'echo hi' })).toBe(true)
diff --git a/apps/desktop/src/app/cron/cron-job-model.ts b/apps/desktop/src/app/cron/cron-job-model.ts
index cbbe43e29d..bf94470b64 100644
--- a/apps/desktop/src/app/cron/cron-job-model.ts
+++ b/apps/desktop/src/app/cron/cron-job-model.ts
@@ -45,6 +45,35 @@ export interface CronEditorSaveValues {
   schedule: string
 }
 
+export interface CronModelChoice {
+  model: string
+  provider: string
+}
+
+/** Encode the provider/model pair as an opaque Select value without delimiter ambiguity. */
+export function cronModelChoiceValue(provider: string, model: string): string {
+  return JSON.stringify([provider, model])
+}
+
+export function parseCronModelChoiceValue(value: string): CronModelChoice | null {
+  try {
+    const parsed: unknown = JSON.parse(value)
+
+    if (
+      !Array.isArray(parsed) ||
+      parsed.length !== 2 ||
+      typeof parsed[0] !== 'string' ||
+      typeof parsed[1] !== 'string'
+    ) {
+      return null
+    }
+
+    return { provider: parsed[0], model: parsed[1] }
+  } catch {
+    return null
+  }
+}
+
 export function parseCronDeliveryTargets(value: string): string[] {
   const targets = value
     .split(',')
diff --git a/apps/desktop/src/app/cron/index.tsx b/apps/desktop/src/app/cron/index.tsx
index cfd9f9138c..41d6435d61 100644
--- a/apps/desktop/src/app/cron/index.tsx
+++ b/apps/desktop/src/app/cron/index.tsx
@@ -77,9 +77,11 @@ import { BlueprintSlotControl, blueprintSlotHelp, cleanBlueprintFieldError, init
 import { mutateAndRefreshCronJobs, refreshCronJobs, triggerAndRefreshCronJobs } from './cron-actions'
 import {
   cronEditorUpdates,
+  cronModelChoiceValue,
   jobIsScriptOnly,
   lastErrorSummary,
   parseCronDeliveryTargets,
+  parseCronModelChoiceValue,
   toggleCronDeliveryTarget,
   validateCronEditor
 } from './cron-job-model'
@@ -1050,8 +1052,8 @@ function CronEditorDialog({
   const [schedule, setSchedule] = useState('')
   const [schedulePreset, setSchedulePreset] = useState('daily')
   const [deliver, setDeliver] = useState(DEFAULT_DELIVER)
-  // Per-job model override, encoded as `${providerSlug}:${model}` (split on the
-  // first ':' when saving). MODEL_DEFAULT_VALUE = follow the global default.
+  // Per-job model override encoded as an opaque provider/model pair.
+  // MODEL_DEFAULT_VALUE = follow the global default.
   const [modelChoice, setModelChoice] = useState(MODEL_DEFAULT_VALUE)
   // Blueprint fills typed slots (time/enum/weekdays/text) instead of the raw
   // cron fields; the backend renders the prompt + schedule from them.
@@ -1106,7 +1108,9 @@ function CronEditorDialog({
     setSchedule(initial ? jobScheduleExpr(initial) : (SCHEDULE_OPTIONS[0].expr ?? ''))
     setSchedulePreset(initial ? scheduleOptionForExpr(jobScheduleExpr(initial)).value : 'daily')
     setDeliver(initial ? jobDeliver(initial) : DEFAULT_DELIVER)
-    setModelChoice(initial && jobModel(initial) ? `${jobProvider(initial)}:${jobModel(initial)}` : MODEL_DEFAULT_VALUE)
+    setModelChoice(
+      initial && jobModel(initial) ? cronModelChoiceValue(jobProvider(initial), jobModel(initial)) : MODEL_DEFAULT_VALUE
+    )
     setSlotValues({})
     setTemplateChoice(editor.mode === 'create' ? (editor.blueprintKey ?? CUSTOM_TEMPLATE) : CUSTOM_TEMPLATE)
     setError(null)
@@ -1149,7 +1153,9 @@ function CronEditorDialog({
   // stored pin visible and re-selectable rather than silently dropping it.
   const modelChoiceKnown =
     modelChoice === MODEL_DEFAULT_VALUE ||
-    modelProviders.some(provider => (provider.models ?? []).some(model => `${provider.slug}:${model}` === modelChoice))
+    modelProviders.some(provider =>
+      (provider.models ?? []).some(model => cronModelChoiceValue(provider.slug, model) === modelChoice)
+    )
 
   async function handleSubmit(event: React.FormEvent) {
     event.preventDefault()
@@ -1172,11 +1178,7 @@ function CronEditorDialog({
       return
     }
 
-    // Decode `${providerSlug}:${model}` — the model half may itself contain
-    // ':' (e.g. openrouter 'anthropic/claude-sonnet-4:beta'), so split once.
-    const overrideIndex = modelChoice === MODEL_DEFAULT_VALUE ? -1 : modelChoice.indexOf(':')
-    const overrideProvider = overrideIndex >= 0 ? modelChoice.slice(0, overrideIndex) : ''
-    const overrideModel = overrideIndex >= 0 ? modelChoice.slice(overrideIndex + 1) : ''
+    const override = parseCronModelChoiceValue(modelChoice)
 
     setSaving(true)
     setError(null)
@@ -1184,10 +1186,10 @@ function CronEditorDialog({
     try {
       await onSave({
         deliver,
-        model: overrideModel,
+        model: override?.model ?? '',
         name: name.trim(),
         prompt: prompt.trim(),
-        provider: overrideProvider,
+        provider: override?.provider ?? '',
         schedule: schedule.trim()
       })
     } catch (err) {
@@ -1357,21 +1359,21 @@ function CronEditorDialog({
                     <SelectItem value={MODEL_DEFAULT_VALUE}>{c.modelDefault}</SelectItem>
                     {!modelChoiceKnown && (
                       <SelectItem className="font-mono" value={modelChoice}>
-                        {modelChoice.slice(modelChoice.indexOf(':') + 1)}
+                        {parseCronModelChoiceValue(modelChoice)?.model ?? modelChoice}
                       </SelectItem>
                     )}
                     {modelProviders.map(provider => (
                       <SelectGroup key={provider.slug}>
                         <SelectLabel>{provider.name}</SelectLabel>
-                        {(provider.models ?? []).map(model => (
-                          <SelectItem
-                            className="font-mono"
-                            key={`${provider.slug}:${model}`}
-                            value={`${provider.slug}:${model}`}
-                          >
-                            {model}
-                          </SelectItem>
-                        ))}
+                        {(provider.models ?? []).map(model => {
+                          const value = cronModelChoiceValue(provider.slug, model)
+
+                          return (
+                            <SelectItem className="font-mono" key={value} value={value}>
+                              {model}
+                            </SelectItem>
+                          )
+                        })}
                       </SelectGroup>
                     ))}
                   </SelectContent>