diff --git a/packages/backend-defaults/src/entrypoints/actionsRegistry/DefaultActionsRegistryService.ts b/packages/backend-defaults/src/entrypoints/actionsRegistry/DefaultActionsRegistryService.ts
index 17523a2ee5..2ecf4d5006 100644
--- a/packages/backend-defaults/src/entrypoints/actionsRegistry/DefaultActionsRegistryService.ts
+++ b/packages/backend-defaults/src/entrypoints/actionsRegistry/DefaultActionsRegistryService.ts
@@ -24,7 +24,7 @@ import {
 } from '@backstage/backend-plugin-api';
 import PromiseRouter from 'express-promise-router';
 import { Router, json } from 'express';
-import { z, ZodType } from 'zod';
+import { z, AnyZodObject } from 'zod';
 import zodToJsonSchema from 'zod-to-json-schema';
 import {
   ForwardedError,
@@ -142,9 +142,10 @@ export class DefaultActionsRegistryService implements ActionsRegistryService {
     return router;
   }
 
-  register<TInputSchema extends ZodType, TOutputSchema extends ZodType>(
-    options: ActionsRegistryActionOptions<TInputSchema, TOutputSchema>,
-  ): void {
+  register<
+    TInputSchema extends AnyZodObject,
+    TOutputSchema extends AnyZodObject,
+  >(options: ActionsRegistryActionOptions<TInputSchema, TOutputSchema>): void {
     const id = `${this.metadata.getId()}:${options.name}`;
 
     if (this.actions.has(id)) {
diff --git a/packages/backend-defaults/src/entrypoints/actionsRegistry/actionsRegistryServiceFactory.test.ts b/packages/backend-defaults/src/entrypoints/actionsRegistry/actionsRegistryServiceFactory.test.ts
index 5d47ff055d..9d6674c0cf 100644
--- a/packages/backend-defaults/src/entrypoints/actionsRegistry/actionsRegistryServiceFactory.test.ts
+++ b/packages/backend-defaults/src/entrypoints/actionsRegistry/actionsRegistryServiceFactory.test.ts
@@ -181,7 +181,7 @@ describe('actionsRegistryServiceFactory', () => {
       });
     });
 
-    it('should allow registering of actions with no schema', async () => {
+    it('should forces registration of input and output schema as objects', async () => {
       const pluginSubject = createBackendPlugin({
         pluginId: 'my-plugin',
         register(reg) {
@@ -195,9 +195,12 @@ describe('actionsRegistryServiceFactory', () => {
                 title: 'Test',
                 description: 'Test',
                 schema: {
+                  // @ts-expect-error - z.undefined is not a valid schema
                   input: z => z.undefined(),
+                  // @ts-expect-error - z.string is not a valid schema
                   output: z => z.string(),
                 },
+                // @ts-expect-error - output is not a valid, needs to be an object
                 action: async () => ({ output: 'ok' }),
               });
             },
diff --git a/packages/backend-plugin-api/report.api.md b/packages/backend-plugin-api/report.api.md
index 68597dcbe1..3b24fcb012 100644
--- a/packages/backend-plugin-api/report.api.md
+++ b/packages/backend-plugin-api/report.api.md
@@ -3,6 +3,7 @@
 > Do not edit this file. It is a report generated by [API Extractor](https://api-extractor.com/).
 
 ```ts
+import { AnyZodObject } from 'zod';
 import { AuthorizePermissionRequest } from '@backstage/plugin-permission-common';
 import { AuthorizePermissionResponse } from '@backstage/plugin-permission-common';
 import { Config } from '@backstage/config';
@@ -27,10 +28,9 @@ import { Readable } from 'stream';
 import type { Request as Request_2 } from 'express';
 import type { Response as Response_2 } from 'express';
 import { z } from 'zod';
-import { ZodType } from 'zod';
 
 // @public (undocumented)
-export type ActionsRegistryActionContext<TInputSchema extends ZodType> = {
+export type ActionsRegistryActionContext<TInputSchema extends AnyZodObject> = {
   input: z.infer<TInputSchema>;
   logger: LoggerService;
   credentials: BackstageCredentials;
@@ -38,8 +38,8 @@ export type ActionsRegistryActionContext<TInputSchema extends ZodType> = {
 
 // @public (undocumented)
 export type ActionsRegistryActionOptions<
-  TInputSchema extends ZodType,
-  TOutputSchema extends ZodType,
+  TInputSchema extends AnyZodObject,
+  TOutputSchema extends AnyZodObject,
 > = {
   name: string;
   title: string;
@@ -60,7 +60,10 @@ export type ActionsRegistryActionOptions<
 // @public (undocumented)
 export interface ActionsRegistryService {
   // (undocumented)
-  register<TInputSchema extends ZodType, TOutputSchema extends ZodType>(
+  register<
+    TInputSchema extends AnyZodObject,
+    TOutputSchema extends AnyZodObject,
+  >(
     options: ActionsRegistryActionOptions<TInputSchema, TOutputSchema>,
   ): void;
 }
diff --git a/packages/backend-plugin-api/src/services/definitions/ActionsRegistryService.ts b/packages/backend-plugin-api/src/services/definitions/ActionsRegistryService.ts
index 3044c84ed8..44df71f41b 100644
--- a/packages/backend-plugin-api/src/services/definitions/ActionsRegistryService.ts
+++ b/packages/backend-plugin-api/src/services/definitions/ActionsRegistryService.ts
@@ -13,14 +13,14 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-import { z, ZodType } from 'zod';
+import { z, AnyZodObject } from 'zod';
 import { LoggerService } from './LoggerService';
 import { BackstageCredentials } from './AuthService';
 
 /**
  * @public
  */
-export type ActionsRegistryActionContext<TInputSchema extends ZodType> = {
+export type ActionsRegistryActionContext<TInputSchema extends AnyZodObject> = {
   input: z.infer<TInputSchema>;
   logger: LoggerService;
   credentials: BackstageCredentials;
@@ -30,8 +30,8 @@ export type ActionsRegistryActionContext<TInputSchema extends ZodType> = {
  * @public
  */
 export type ActionsRegistryActionOptions<
-  TInputSchema extends ZodType,
-  TOutputSchema extends ZodType,
+  TInputSchema extends AnyZodObject,
+  TOutputSchema extends AnyZodObject,
 > = {
   name: string;
   title: string;
@@ -53,7 +53,10 @@ export type ActionsRegistryActionOptions<
  * @public
  */
 export interface ActionsRegistryService {
-  register<TInputSchema extends ZodType, TOutputSchema extends ZodType>(
+  register<
+    TInputSchema extends AnyZodObject,
+    TOutputSchema extends AnyZodObject,
+  >(
     options: ActionsRegistryActionOptions<TInputSchema, TOutputSchema>,
   ): void;
 }