diff --git a/src/injection/Injector.ts b/src/injection/Injector.ts
index 35e53e24..9cfe6d90 100644
--- a/src/injection/Injector.ts
+++ b/src/injection/Injector.ts
@@ -145,7 +145,12 @@ export function injectUserForBuildTrigger() {
 
                 if (!tokenMatches) {
                     Logger.e('Token mismatch for app build')
-                    next()
+                    res.send(
+                        new BaseApi(
+                            ApiStatusCodes.STATUS_ERROR_NOT_AUTHORIZED,
+                            'The request is not authorized.'
+                        )
+                    )
                     return
                 }
 
diff --git a/tests/BuildTriggerInjection.test.ts b/tests/BuildTriggerInjection.test.ts
new file mode 100644
index 00000000..545f672c
--- /dev/null
+++ b/tests/BuildTriggerInjection.test.ts
@@ -0,0 +1,53 @@
+jest.mock('../src/docker/DockerApi', () => ({
+    __esModule: true,
+    default: { get: jest.fn(() => ({})) },
+}))
+
+jest.mock('../src/datastore/DataStoreProvider', () => ({
+    __esModule: true,
+    default: { getDataStore: jest.fn() },
+}))
+
+import DataStoreProvider from '../src/datastore/DataStoreProvider'
+import { injectUserForBuildTrigger } from '../src/injection/Injector'
+
+describe('build trigger token injection', () => {
+    it('returns not authorized for a mismatched app deploy token', async () => {
+        const getAppDefinition = jest.fn().mockResolvedValue({
+            appDeployTokenConfig: {
+                enabled: true,
+                appDeployToken: 'expected-token',
+            },
+        })
+        ;(DataStoreProvider.getDataStore as jest.Mock).mockReturnValue({
+            getAppsDataStore: () => ({ getAppDefinition }),
+        })
+
+        let resolveResponse: () => void = () => undefined
+        const responseSent = new Promise<void>((resolve) => {
+            resolveResponse = resolve
+        })
+        const response = {
+            locals: { namespace: 'captain' },
+            send: jest.fn(() => resolveResponse()),
+        }
+        const request = {
+            header: jest.fn((name: string) =>
+                name === 'x-captain-app-token' ? 'invalid-token' : undefined
+            ),
+            params: { appName: 'test-app' },
+        }
+        const next = jest.fn()
+
+        injectUserForBuildTrigger()(request as any, response as any, next)
+        await responseSent
+
+        expect(response.send).toHaveBeenCalledWith(
+            expect.objectContaining({
+                status: 1102,
+                description: 'The request is not authorized.',
+            })
+        )
+        expect(next).not.toHaveBeenCalled()
+    })
+})