diff --git a/src/loader/egg_loader.ts b/src/loader/egg_loader.ts
index 16edcca5..4d2b5c83 100644
--- a/src/loader/egg_loader.ts
+++ b/src/loader/egg_loader.ts
@@ -823,7 +823,7 @@ export class EggLoader {
     this.configMeta = {};
 
     const target: EggAppConfig = {
-      appMiddleware: [],
+      middleware: [],
       coreMiddleware: [],
     };
 
@@ -855,8 +855,8 @@ export class EggLoader {
     extend(true, target, envConfig);
 
     // You can manipulate the order of app.config.coreMiddleware and app.config.appMiddleware in app.js
-    target.coreMiddlewares = target.coreMiddleware;
-    target.appMiddlewares = target.middleware;
+    target.coreMiddleware = target.coreMiddlewares = target.coreMiddleware || [];
+    target.appMiddleware = target.appMiddlewares = target.middleware || [];
 
     this.config = target;
     debug('[loadConfig] all config: %o', this.config);
diff --git a/src/types.ts b/src/types.ts
index d56ae9ae..e9cccc83 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -48,7 +48,7 @@ export interface CustomLoaderConfigItem {
 
 export interface EggAppConfig extends Record<string, any> {
   coreMiddleware: string[];
-  appMiddleware: string[];
+  middleware: string[];
   customLoader?: Record<string, CustomLoaderConfigItem>;
   controller?: {
     supportParams?: boolean;
diff --git a/test/index.test.ts b/test/index.test.ts
index 475f9482..1f62f630 100644
--- a/test/index.test.ts
+++ b/test/index.test.ts
@@ -37,9 +37,9 @@ describe('test/index.test.ts', () => {
   it('should expose types', () => {
     const config = {
       coreMiddleware: [],
-      appMiddleware: [],
+      middleware: [],
     } as EggAppConfig;
-    assert(config.appMiddleware);
+    assert(config.middleware);
     assert(config.coreMiddleware);
   });
 });
diff --git a/test/loader/mixin/load_custom_loader.test.ts b/test/loader/mixin/load_custom_loader.test.ts
index 7df1fdc2..c80d8ffd 100644
--- a/test/loader/mixin/load_custom_loader.test.ts
+++ b/test/loader/mixin/load_custom_loader.test.ts
@@ -103,7 +103,7 @@ describe('test/loader/mixin/load_custom_loader.test.ts', () => {
     try {
       app.loader.config = {
         coreMiddleware: [],
-        appMiddleware: [],
+        middleware: [],
         customLoader: {
           config: {
             directory: 'app/config',