diff --git a/packages/router-generator/src/config.ts b/packages/router-generator/src/config.ts
index f9680d9d364..0dcb0db65f0 100644
--- a/packages/router-generator/src/config.ts
+++ b/packages/router-generator/src/config.ts
@@ -15,6 +15,10 @@ const tokenMatcherSchema = z.union([
   tokenJsonRegexSchema,
 ])
 
+const stringArrayFactorySchema = z.custom<() => Array<string>>(
+  (value) => typeof value === 'function',
+)
+
 export type TokenMatcherJson = string | z.infer<typeof tokenJsonRegexSchema>
 
 export type TokenMatcher = z.infer<typeof tokenMatcherSchema>
@@ -61,7 +65,7 @@ export const configSchema = baseConfigSchema.extend({
   routeTreeFileFooter: z
     .union([
       z.array(z.string()).optional().default([]),
-      z.function().returns(z.array(z.string())),
+      stringArrayFactorySchema,
     ])
     .optional(),
   autoCodeSplitting: z.boolean().optional(),
diff --git a/packages/router-generator/tests/config.test.ts b/packages/router-generator/tests/config.test.ts
index 1290920040a..36cedecea12 100644
--- a/packages/router-generator/tests/config.test.ts
+++ b/packages/router-generator/tests/config.test.ts
@@ -30,4 +30,18 @@ describe('load config tests', () => {
       )
     },
   )
+
+  it('accepts routeTreeFileFooter as a function', () => {
+    const routeTreeFileFooter = () => ['// append']
+    const resolvedConfig = getConfig({ routeTreeFileFooter })
+
+    expect(resolvedConfig.routeTreeFileFooter).toBe(routeTreeFileFooter)
+  })
+
+  it('accepts routeTreeFileFooter as an array', () => {
+    const routeTreeFileFooter = ['// append']
+    const resolvedConfig = getConfig({ routeTreeFileFooter })
+
+    expect(resolvedConfig.routeTreeFileFooter).toEqual(routeTreeFileFooter)
+  })
 })