diff --git a/.changeset/khaki-cheetahs-provide.md b/.changeset/khaki-cheetahs-provide.md
new file mode 100644
index 00000000..29af2bdc
--- /dev/null
+++ b/.changeset/khaki-cheetahs-provide.md
@@ -0,0 +1,5 @@
+---
+'@hono/zod-openapi': minor
+---
+
+feat: bump `zod-to-openapi` supports ESM
diff --git a/packages/zod-openapi/.yarn/install-state.gz b/packages/zod-openapi/.yarn/install-state.gz
index 10a1ddc8..43018591 100644
Binary files a/packages/zod-openapi/.yarn/install-state.gz and b/packages/zod-openapi/.yarn/install-state.gz differ
diff --git a/packages/zod-openapi/package.json b/packages/zod-openapi/package.json
index cf125812..b684a819 100644
--- a/packages/zod-openapi/package.json
+++ b/packages/zod-openapi/package.json
@@ -42,16 +42,16 @@
   },
   "devDependencies": {
     "@cloudflare/workers-types": "^4.20240117.0",
-    "hono": "^3.11.7",
+    "hono": "^4.2.2",
     "jest": "^29.7.0",
     "openapi3-ts": "^4.1.2",
     "tsup": "^8.0.1",
-    "typescript": "^5.3.3",
-    "vitest": "^1.0.1",
+    "typescript": "^5.4.4",
+    "vitest": "^1.4.0",
     "zod": "^3.22.1"
   },
   "dependencies": {
-    "@asteasolutions/zod-to-openapi": "^5.5.0",
+    "@asteasolutions/zod-to-openapi": "^7.0.0",
     "@hono/zod-validator": "0.2.1"
   },
   "engines": {
diff --git a/packages/zod-openapi/src/index.ts b/packages/zod-openapi/src/index.ts
index 1e4cc3f2..887fafcf 100644
--- a/packages/zod-openapi/src/index.ts
+++ b/packages/zod-openapi/src/index.ts
@@ -76,7 +76,10 @@ type InputTypeJson<R extends RouteConfig> = R['request'] extends RequestTypes
     ? R['request']['body']['content'] extends ZodContentObject
       ? IsJson<keyof R['request']['body']['content']> extends never
         ? {}
-        : R['request']['body']['content'][keyof R['request']['body']['content']]['schema'] extends ZodSchema<any>
+        : R['request']['body']['content'][keyof R['request']['body']['content']] extends Record<
+            'schema',
+            ZodSchema<any>
+          >
         ? {
             in: {
               json: z.input<
@@ -99,7 +102,10 @@ type InputTypeForm<R extends RouteConfig> = R['request'] extends RequestTypes
     ? R['request']['body']['content'] extends ZodContentObject
       ? IsForm<keyof R['request']['body']['content']> extends never
         ? {}
-        : R['request']['body']['content'][keyof R['request']['body']['content']]['schema'] extends ZodSchema<any>
+        : R['request']['body']['content'][keyof R['request']['body']['content']] extends Record<
+            'schema',
+            ZodSchema<any>
+          >
         ? {
             in: {
               form: z.input<
@@ -127,7 +133,7 @@ type OutputType<R extends RouteConfig> = R['responses'] extends Record<infer _,
     ? C['content'] extends ZodContentObject
       ? IsJson<keyof C['content']> extends never
         ? {}
-        : C['content'][keyof C['content']]['schema'] extends ZodSchema
+        : C['content'][keyof C['content']] extends Record<'schema', ZodSchema>
         ? z.infer<C['content'][keyof C['content']]['schema']>
         : {}
       : {}
@@ -250,7 +256,11 @@ export class OpenAPIHono<
         : HandlerAllResponse<OutputType<R>>
     >,
     hook: Hook<I, E, P, OutputType<R>> | undefined = this.defaultHook
-  ): OpenAPIHono<E, S & ToSchema<R['method'], MergePath<BasePath, P>, I['in'], OutputType<R>>, BasePath> => {
+  ): OpenAPIHono<
+    E,
+    S & ToSchema<R['method'], MergePath<BasePath, P>, I['in'], OutputType<R>>,
+    BasePath
+  > => {
     this.openAPIRegistry.registerPath(route)
 
     const validators: MiddlewareHandler[] = []
@@ -279,22 +289,23 @@ export class OpenAPIHono<
 
     if (bodyContent) {
       for (const mediaType of Object.keys(bodyContent)) {
+        if (!bodyContent[mediaType]) {
+          continue
+        }
+        const schema = (bodyContent[mediaType] as ZodMediaTypeObject)['schema']
+        if (!(schema instanceof ZodType)) {
+          continue
+        }
         if (mediaType.startsWith('application/json')) {
-          const schema = bodyContent[mediaType]['schema']
-          if (schema instanceof ZodType) {
-            const validator = zValidator('json', schema as any, hook as any)
-            validators.push(validator as any)
-          }
+          const validator = zValidator('json', schema, hook as any)
+          validators.push(validator as any)
         }
         if (
           mediaType.startsWith('multipart/form-data') ||
           mediaType.startsWith('application/x-www-form-urlencoded')
         ) {
-          const schema = bodyContent[mediaType]['schema']
-          if (schema instanceof ZodType) {
-            const validator = zValidator('form', schema as any, hook as any)
-            validators.push(validator as any)
-          }
+          const validator = zValidator('form', schema, hook as any)
+          validators.push(validator as any)
         }
       }
     }
@@ -409,7 +420,7 @@ export class OpenAPIHono<
   }
 
   basePath<SubPath extends string>(path: SubPath): OpenAPIHono<E, S, MergePath<BasePath, SubPath>> {
-    return new OpenAPIHono({...super.basePath(path) as any, defaultHook: this.defaultHook})
+    return new OpenAPIHono({ ...(super.basePath(path) as any), defaultHook: this.defaultHook })
   }
 }
 
diff --git a/packages/zod-openapi/test/index.test-d.ts b/packages/zod-openapi/test/index.test-d.ts
index 03051e3a..062c04be 100644
--- a/packages/zod-openapi/test/index.test-d.ts
+++ b/packages/zod-openapi/test/index.test-d.ts
@@ -70,7 +70,7 @@ describe('Types', () => {
       '/'
     >
     expectTypeOf(appRoutes).toMatchTypeOf<H>()
-  });
+  })
 })
 
 describe('Input types', () => {
@@ -83,7 +83,7 @@ describe('Input types', () => {
           name: 'id',
           in: 'path',
         },
-        example: 123,
+        example: '123',
       }),
   })
 
@@ -96,7 +96,7 @@ describe('Input types', () => {
           name: 'age',
           in: 'query',
         },
-        example: 42,
+        example: '42',
       }),
   })
 
@@ -162,7 +162,7 @@ describe('Input types', () => {
       const { sex } = c.req.valid('json')
       assertType<'male' | 'female'>(sex)
 
-      return c.jsonT({
+      return c.json({
         id,
         age,
         sex,
diff --git a/packages/zod-openapi/test/index.test.ts b/packages/zod-openapi/test/index.test.ts
index 8a86d897..3f24e1b5 100644
--- a/packages/zod-openapi/test/index.test.ts
+++ b/packages/zod-openapi/test/index.test.ts
@@ -561,7 +561,7 @@ describe('Input types', () => {
           name: 'id',
           in: 'path',
         },
-        example: 123,
+        example: '123',
       }),
   })
 
@@ -574,7 +574,7 @@ describe('Input types', () => {
           name: 'age',
           in: 'query',
         },
-        example: 42,
+        example: '42',
       }),
   })
 
@@ -704,7 +704,7 @@ describe('Routers', () => {
   })
   it('Should include definitions from nested routers', async () => {
     const router = new OpenAPIHono().openapi(route, (ctx) => {
-      return ctx.jsonT({ id: 123 })
+      return ctx.json({ id: 123 })
     })
 
     router.openAPIRegistry.register('Id', z.number())
@@ -827,7 +827,7 @@ describe('basePath()', () => {
   it('Should retain defaultHook of the parent app', async () => {
     const defaultHook = () => {}
     const app = new OpenAPIHono({
-      defaultHook
+      defaultHook,
     }).basePath('/api')
     expect(app.defaultHook).toBeDefined()
     expect(app.defaultHook).toBe(defaultHook)
diff --git a/packages/zod-openapi/yarn.lock b/packages/zod-openapi/yarn.lock
index 7a9f7d08..f11fb5f9 100644
--- a/packages/zod-openapi/yarn.lock
+++ b/packages/zod-openapi/yarn.lock
@@ -15,14 +15,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@asteasolutions/zod-to-openapi@npm:^5.5.0":
-  version: 5.5.0
-  resolution: "@asteasolutions/zod-to-openapi@npm:5.5.0"
+"@asteasolutions/zod-to-openapi@npm:^7.0.0":
+  version: 7.0.0
+  resolution: "@asteasolutions/zod-to-openapi@npm:7.0.0"
   dependencies:
     openapi3-ts: "npm:^4.1.2"
   peerDependencies:
     zod: ^3.20.2
-  checksum: 3cac318d4bf2efe88175002d0ee66a299207c29dbb3dd5f353b1fcf46bb7117e9f203c6ae7093d740182c94fd625703bf2ac1d721a6c1d64adfc977d0f00d909
+  checksum: 120499b6d997bd3fa21b4e6600f42d6b9201e2a85a7656b722a02c712d6a9fd7c474bf62ad31f76646fbd129d75331408ad3ed5c350c1436856ef306966a33e1
   languageName: node
   linkType: hard
 
@@ -591,15 +591,15 @@ __metadata:
   version: 0.0.0-use.local
   resolution: "@hono/zod-openapi@workspace:."
   dependencies:
-    "@asteasolutions/zod-to-openapi": "npm:^5.5.0"
+    "@asteasolutions/zod-to-openapi": "npm:^7.0.0"
     "@cloudflare/workers-types": "npm:^4.20240117.0"
     "@hono/zod-validator": "npm:0.2.1"
-    hono: "npm:^3.11.7"
+    hono: "npm:^4.2.2"
     jest: "npm:^29.7.0"
     openapi3-ts: "npm:^4.1.2"
     tsup: "npm:^8.0.1"
-    typescript: "npm:^5.3.3"
-    vitest: "npm:^1.0.1"
+    typescript: "npm:^5.4.4"
+    vitest: "npm:^1.4.0"
     zod: "npm:^3.22.1"
   peerDependencies:
     hono: ">=3.11.3"
@@ -1209,57 +1209,57 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@vitest/expect@npm:1.2.2":
-  version: 1.2.2
-  resolution: "@vitest/expect@npm:1.2.2"
+"@vitest/expect@npm:1.4.0":
+  version: 1.4.0
+  resolution: "@vitest/expect@npm:1.4.0"
   dependencies:
-    "@vitest/spy": "npm:1.2.2"
-    "@vitest/utils": "npm:1.2.2"
+    "@vitest/spy": "npm:1.4.0"
+    "@vitest/utils": "npm:1.4.0"
     chai: "npm:^4.3.10"
-  checksum: 920e80b956d9d5ef7909cbe2bf883c8556da11c5123ea037396cb672d7038116c9773bd36915a3df7be2ffd76b661d5a6487e7e5ded78f39e2500cb36ae81e59
+  checksum: 2d6a657afc674adb78ad6609ecf61a94355b080cf90f922e05193b5b33b37d486c9b66a52270f1f367c16d626bcb8323368519dae096a992190898e03280b5e0
   languageName: node
   linkType: hard
 
-"@vitest/runner@npm:1.2.2":
-  version: 1.2.2
-  resolution: "@vitest/runner@npm:1.2.2"
+"@vitest/runner@npm:1.4.0":
+  version: 1.4.0
+  resolution: "@vitest/runner@npm:1.4.0"
   dependencies:
-    "@vitest/utils": "npm:1.2.2"
+    "@vitest/utils": "npm:1.4.0"
     p-limit: "npm:^5.0.0"
     pathe: "npm:^1.1.1"
-  checksum: 25a9c03cca5b40738fe606757b14ee9d60d25193115b4674e3cc402c2b2c3844d234902d48bfa7646cb205455ea27891fef96733e033a570b85fe74ed29ff81c
+  checksum: 87a5bdde5c48e3258ecd2716994da20c8eec63acaf63a0db724513a42701bc644728009a7301d78b8775d8004c7ce1ddb8bde6495066d864c532bc117783aa91
   languageName: node
   linkType: hard
 
-"@vitest/snapshot@npm:1.2.2":
-  version: 1.2.2
-  resolution: "@vitest/snapshot@npm:1.2.2"
+"@vitest/snapshot@npm:1.4.0":
+  version: 1.4.0
+  resolution: "@vitest/snapshot@npm:1.4.0"
   dependencies:
     magic-string: "npm:^0.30.5"
     pathe: "npm:^1.1.1"
     pretty-format: "npm:^29.7.0"
-  checksum: 0f8a69a289aa6466c7dd56f8327190d56a0bc7ad10412127de001c94784f6dba5e5bccb757def21f565f4efa3e00c307b92e8b6c302f11fc57889b743ba18a95
+  checksum: 6f089d1dbe43556779479bc309b0a8fc7e0229843c40efb4dabcf99ccf9a6fa859dd38c13674616a955801442730aca55151cbd52bb22d41d9a335060e03759b
   languageName: node
   linkType: hard
 
-"@vitest/spy@npm:1.2.2":
-  version: 1.2.2
-  resolution: "@vitest/spy@npm:1.2.2"
+"@vitest/spy@npm:1.4.0":
+  version: 1.4.0
+  resolution: "@vitest/spy@npm:1.4.0"
   dependencies:
     tinyspy: "npm:^2.2.0"
-  checksum: 5480048d26c0d82b524317552fbdcc05fed6ea626d887620647826453a344798a360f2a75af477512a1569b1b6c918eae62338e8b35575f875fc2d7ef51419f3
+  checksum: 847bc3085d0aa2e039aa42d803cf2dc94596aab3a63de7d364933d24ed9e0781b7d3d4bd222df202f92bae83e9c37b2893b9f24a2de7d83b6930b7b1acf43516
   languageName: node
   linkType: hard
 
-"@vitest/utils@npm:1.2.2":
-  version: 1.2.2
-  resolution: "@vitest/utils@npm:1.2.2"
+"@vitest/utils@npm:1.4.0":
+  version: 1.4.0
+  resolution: "@vitest/utils@npm:1.4.0"
   dependencies:
     diff-sequences: "npm:^29.6.3"
     estree-walker: "npm:^3.0.3"
     loupe: "npm:^2.3.7"
     pretty-format: "npm:^29.7.0"
-  checksum: 32449cb7eca8ecea56e0fce280c9770f65fa6b60bbba73be06ca2891096818899b4b3220bd3c815df8beb4266034db394fcf235e4de8959cce686b8b360948d1
+  checksum: cfa352484f0ea2614444a94fc35979bea94fac64e9756238c685ae74bcd027893a1798b9d6d92c1cdd454b1f7f08f453d0cca108274f0449b6f5efd345822a4c
   languageName: node
   linkType: hard
 
@@ -1277,7 +1277,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"acorn@npm:^8.10.0, acorn@npm:^8.11.3":
+"acorn@npm:^8.11.3":
   version: 8.11.3
   resolution: "acorn@npm:8.11.3"
   bin:
@@ -2379,10 +2379,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"hono@npm:^3.11.7":
-  version: 3.12.8
-  resolution: "hono@npm:3.12.8"
-  checksum: 98450510d4e91a1f2ceec6c7d4e7e01c5dd81e9ff1fc68601fcfa64dd95e01e09a27e30a109004d7395f0aaac5a2ba6f975d7350c7c53053f85d8a5ad4cd07b1
+"hono@npm:^4.2.2":
+  version: 4.2.2
+  resolution: "hono@npm:4.2.2"
+  checksum: 4f423ff808c105341d2802192abe9070c5f6fc4a45da51842a5f5f2111b4c333ef4aea2720a585e16996944cc0cedf68657c57df1d150f1382f21fc18e814b42
   languageName: node
   linkType: hard
 
@@ -3128,6 +3128,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"js-tokens@npm:^9.0.0":
+  version: 9.0.0
+  resolution: "js-tokens@npm:9.0.0"
+  checksum: 4ad1c12f47b8c8b2a3a99e29ef338c1385c7b7442198a425f3463f3537384dab6032012791bfc2f056ea5ecdb06b1ed4f70e11a3ab3f388d3dcebfe16a52b27d
+  languageName: node
+  linkType: hard
+
 "js-yaml@npm:^3.13.1":
   version: 3.14.1
   resolution: "js-yaml@npm:3.14.1"
@@ -4292,12 +4299,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"strip-literal@npm:^1.3.0":
-  version: 1.3.0
-  resolution: "strip-literal@npm:1.3.0"
+"strip-literal@npm:^2.0.0":
+  version: 2.1.0
+  resolution: "strip-literal@npm:2.1.0"
   dependencies:
-    acorn: "npm:^8.10.0"
-  checksum: 3c0c9ee41eb346e827eede61ef288457f53df30e3e6ff8b94fa81b636933b0c13ca4ea5c97d00a10d72d04be326da99ac819f8769f0c6407ba8177c98344a916
+    js-tokens: "npm:^9.0.0"
+  checksum: bc8b8c8346125ae3c20fcdaf12e10a498ff85baf6f69597b4ab2b5fbf2e58cfd2827f1a44f83606b852da99a5f6c8279770046ddea974c510c17c98934c9cc24
   languageName: node
   linkType: hard
 
@@ -4518,23 +4525,23 @@ __metadata:
   languageName: node
   linkType: hard
 
-"typescript@npm:^5.3.3":
-  version: 5.3.3
-  resolution: "typescript@npm:5.3.3"
+"typescript@npm:^5.4.4":
+  version: 5.4.4
+  resolution: "typescript@npm:5.4.4"
   bin:
     tsc: bin/tsc
     tsserver: bin/tsserver
-  checksum: e33cef99d82573624fc0f854a2980322714986bc35b9cb4d1ce736ed182aeab78e2cb32b385efa493b2a976ef52c53e20d6c6918312353a91850e2b76f1ea44f
+  checksum: 4d8de0291204ed61ca97ad0cba2ce064e09c4988ca1c451c787e4653ba76296ba35177a52694e8a00cf4ef899d0ee83338663b926d8b7d55167ff0ba81549999
   languageName: node
   linkType: hard
 
-"typescript@patch:typescript@npm%3A^5.3.3#optional!builtin<compat/typescript>":
-  version: 5.3.3
-  resolution: "typescript@patch:typescript@npm%3A5.3.3#optional!builtin<compat/typescript>::version=5.3.3&hash=e012d7"
+"typescript@patch:typescript@npm%3A^5.4.4#optional!builtin<compat/typescript>":
+  version: 5.4.4
+  resolution: "typescript@patch:typescript@npm%3A5.4.4#optional!builtin<compat/typescript>::version=5.4.4&hash=e012d7"
   bin:
     tsc: bin/tsc
     tsserver: bin/tsserver
-  checksum: 1d0a5f4ce496c42caa9a30e659c467c5686eae15d54b027ee7866744952547f1be1262f2d40de911618c242b510029d51d43ff605dba8fb740ec85ca2d3f9500
+  checksum: 413a0714a2b554bef8d39a386e5d25df22c625dd677d7260c1a08625016e46ce5f79dae0812641a22ab37c905370b407dc6838e11d4f10845821127d42221876
   languageName: node
   linkType: hard
 
@@ -4595,9 +4602,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"vite-node@npm:1.2.2":
-  version: 1.2.2
-  resolution: "vite-node@npm:1.2.2"
+"vite-node@npm:1.4.0":
+  version: 1.4.0
+  resolution: "vite-node@npm:1.4.0"
   dependencies:
     cac: "npm:^6.7.14"
     debug: "npm:^4.3.4"
@@ -4606,7 +4613,7 @@ __metadata:
     vite: "npm:^5.0.0"
   bin:
     vite-node: vite-node.mjs
-  checksum: 39a5b9d9c806a012aab208eee0f59e4e12446ec19a4cf149a6459e7ff86491c289e189fda4f55a63b7e37d713f5edbda0e9efed95af4f7ebefa6d39eee093c0b
+  checksum: bc8eb01dd03c2cc306be2bf35efe789d6a3e8ca1d89d635d3154a9af0213f7609c94ef849f30a01f04535b31e729aee49468275e267693a42c32845fbd2a6721
   languageName: node
   linkType: hard
 
@@ -4650,17 +4657,16 @@ __metadata:
   languageName: node
   linkType: hard
 
-"vitest@npm:^1.0.1":
-  version: 1.2.2
-  resolution: "vitest@npm:1.2.2"
+"vitest@npm:^1.4.0":
+  version: 1.4.0
+  resolution: "vitest@npm:1.4.0"
   dependencies:
-    "@vitest/expect": "npm:1.2.2"
-    "@vitest/runner": "npm:1.2.2"
-    "@vitest/snapshot": "npm:1.2.2"
-    "@vitest/spy": "npm:1.2.2"
-    "@vitest/utils": "npm:1.2.2"
+    "@vitest/expect": "npm:1.4.0"
+    "@vitest/runner": "npm:1.4.0"
+    "@vitest/snapshot": "npm:1.4.0"
+    "@vitest/spy": "npm:1.4.0"
+    "@vitest/utils": "npm:1.4.0"
     acorn-walk: "npm:^8.3.2"
-    cac: "npm:^6.7.14"
     chai: "npm:^4.3.10"
     debug: "npm:^4.3.4"
     execa: "npm:^8.0.1"
@@ -4669,17 +4675,17 @@ __metadata:
     pathe: "npm:^1.1.1"
     picocolors: "npm:^1.0.0"
     std-env: "npm:^3.5.0"
-    strip-literal: "npm:^1.3.0"
+    strip-literal: "npm:^2.0.0"
     tinybench: "npm:^2.5.1"
     tinypool: "npm:^0.8.2"
     vite: "npm:^5.0.0"
-    vite-node: "npm:1.2.2"
+    vite-node: "npm:1.4.0"
     why-is-node-running: "npm:^2.2.2"
   peerDependencies:
     "@edge-runtime/vm": "*"
     "@types/node": ^18.0.0 || >=20.0.0
-    "@vitest/browser": ^1.0.0
-    "@vitest/ui": ^1.0.0
+    "@vitest/browser": 1.4.0
+    "@vitest/ui": 1.4.0
     happy-dom: "*"
     jsdom: "*"
   peerDependenciesMeta:
@@ -4697,7 +4703,7 @@ __metadata:
       optional: true
   bin:
     vitest: vitest.mjs
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   languageName: node
   linkType: hard