diff --git a/src/manifest.ts b/src/manifest.ts
index 06cddc406..1549170ef 100644
--- a/src/manifest.ts
+++ b/src/manifest.ts
@@ -7,6 +7,7 @@ import type { FunctionResult } from './utils/format_result.js'
 import type { Route } from './utils/routes.js'
 
 interface ManifestFunction {
+  buildData?: Record<string, unknown>
   invocationMode?: InvocationMode
   mainFile: string
   name: string
@@ -55,6 +56,7 @@ const formatFunctionForManifest = ({
   routes,
   runtime,
   runtimeVersion,
+  runtimeAPIVersion,
   schedule,
 }: FunctionResult): ManifestFunction => {
   const manifestFunction: ManifestFunction = {
@@ -62,6 +64,7 @@ const formatFunctionForManifest = ({
     displayName,
     generator,
     invocationMode,
+    buildData: { runtimeAPIVersion },
     mainFile,
     name,
     runtimeVersion,
diff --git a/tests/v2api.test.ts b/tests/v2api.test.ts
index 237527e88..274ed8bf9 100644
--- a/tests/v2api.test.ts
+++ b/tests/v2api.test.ts
@@ -217,7 +217,7 @@ describe.runIf(semver.gte(nodeVersion, '18.13.0'))('V2 functions API', () => {
       },
     })
 
-    expect.assertions(files.length + 1)
+    expect.assertions(files.length + 2)
 
     for (const file of files) {
       switch (file.name) {
@@ -256,6 +256,7 @@ describe.runIf(semver.gte(nodeVersion, '18.13.0'))('V2 functions API', () => {
     const manifestString = await readFile(manifestPath, { encoding: 'utf8' })
     const manifest = JSON.parse(manifestString)
     expect(manifest.functions[0].routes[0].methods).toEqual(['GET', 'POST'])
+    expect(manifest.functions[0].buildData.runtimeAPIVersion).toEqual(2)
   })
 
   test('Flags invalid values of the `path` in-source configuration property as user errors', async () => {