diff --git a/src/client/interfaces/OperationParameter.d.ts b/src/client/interfaces/OperationParameter.d.ts
index 403d57e2..77c0da77 100644
--- a/src/client/interfaces/OperationParameter.d.ts
+++ b/src/client/interfaces/OperationParameter.d.ts
@@ -3,4 +3,5 @@ import type { Model } from './Model';
 export interface OperationParameter extends Model {
     in: 'path' | 'query' | 'header' | 'formData' | 'body' | 'cookie';
     prop: string;
+    mediaType: string | null;
 }
diff --git a/src/openApi/v2/parser/getOperationParameter.ts b/src/openApi/v2/parser/getOperationParameter.ts
index de18c71a..2b8ab927 100644
--- a/src/openApi/v2/parser/getOperationParameter.ts
+++ b/src/openApi/v2/parser/getOperationParameter.ts
@@ -42,6 +42,7 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
         enum: [],
         enums: [],
         properties: [],
+        mediaType: null,
     };
 
     if (parameter.$ref) {
diff --git a/src/openApi/v3/parser/getMediaType.ts b/src/openApi/v3/parser/getMediaType.ts
new file mode 100644
index 00000000..98840ffc
--- /dev/null
+++ b/src/openApi/v3/parser/getMediaType.ts
@@ -0,0 +1,10 @@
+import type { Dictionary } from '../../../utils/types';
+import type { OpenApi } from '../interfaces/OpenApi';
+import type { OpenApiMediaType } from '../interfaces/OpenApiMediaType';
+
+export function getMediaType(openApi: OpenApi, content: Dictionary<OpenApiMediaType>): string | null {
+    return (
+        Object.keys(content).find(key => ['application/json-patch+json', 'application/json', 'text/json', 'text/plain', 'multipart/mixed', 'multipart/related', 'multipart/batch'].includes(key)) ||
+        null
+    );
+}
diff --git a/src/openApi/v3/parser/getOperationParameter.ts b/src/openApi/v3/parser/getOperationParameter.ts
index b126fc9b..27976edc 100644
--- a/src/openApi/v3/parser/getOperationParameter.ts
+++ b/src/openApi/v3/parser/getOperationParameter.ts
@@ -27,6 +27,7 @@ export function getOperationParameter(openApi: OpenApi, parameter: OpenApiParame
         enum: [],
         enums: [],
         properties: [],
+        mediaType: null,
     };
 
     if (parameter.$ref) {
diff --git a/src/openApi/v3/parser/getOperationRequestBody.ts b/src/openApi/v3/parser/getOperationRequestBody.ts
index 321c68e6..a42dbae7 100644
--- a/src/openApi/v3/parser/getOperationRequestBody.ts
+++ b/src/openApi/v3/parser/getOperationRequestBody.ts
@@ -4,6 +4,7 @@ import type { OpenApi } from '../interfaces/OpenApi';
 import type { OpenApiRequestBody } from '../interfaces/OpenApiRequestBody';
 import { getComment } from './getComment';
 import { getContent } from './getContent';
+import { getMediaType } from './getMediaType';
 import { getModel } from './getModel';
 import { getType } from './getType';
 
@@ -27,11 +28,14 @@ export function getOperationRequestBody(openApi: OpenApi, parameter: OpenApiRequ
         enum: [],
         enums: [],
         properties: [],
+        mediaType: null,
     };
 
     if (parameter.content) {
         const schema = getContent(openApi, parameter.content);
+        const mediaType = getMediaType(openApi, parameter.content);
         if (schema) {
+            requestBody.mediaType = mediaType;
             if (schema?.$ref) {
                 const model = getType(schema.$ref);
                 requestBody.export = 'reference';
diff --git a/src/templates/core/ApiRequestOptions.hbs b/src/templates/core/ApiRequestOptions.hbs
index dc33aac8..1419dab0 100644
--- a/src/templates/core/ApiRequestOptions.hbs
+++ b/src/templates/core/ApiRequestOptions.hbs
@@ -8,6 +8,7 @@ export type ApiRequestOptions = {
     readonly query?: Record<string, any>;
     readonly formData?: Record<string, any>;
     readonly body?: any;
+    readonly bodyMediaType?: string;
     readonly responseHeader?: string;
     readonly errors?: Record<number, string>;
 }
diff --git a/src/templates/core/fetch/getHeaders.hbs b/src/templates/core/fetch/getHeaders.hbs
index 9b35a8b5..b4e6d1b2 100644
--- a/src/templates/core/fetch/getHeaders.hbs
+++ b/src/templates/core/fetch/getHeaders.hbs
@@ -20,12 +20,16 @@ async function getHeaders(options: ApiRequestOptions): Promise<Headers> {
     }
 
     if (options.body) {
-        if (isBlob(options.body)) {
-            headers.append('Content-Type', options.body.type || 'application/octet-stream');
-        } else if (isString(options.body)) {
-            headers.append('Content-Type', 'text/plain');
+        if (options.bodyMediaType) {
+            headers.append('Content-Type', options.bodyMediaType);
         } else {
-            headers.append('Content-Type', 'application/json');
+            if (isBlob(options.body)) {
+                headers.append('Content-Type', options.body.type || 'application/octet-stream');
+            } else if (isString(options.body)) {
+                headers.append('Content-Type', 'text/plain');
+            } else {
+                headers.append('Content-Type', 'application/json');
+            }
         }
     }
     return headers;
diff --git a/src/templates/core/fetch/getRequestBody.hbs b/src/templates/core/fetch/getRequestBody.hbs
index 09df2d0b..97b148eb 100644
--- a/src/templates/core/fetch/getRequestBody.hbs
+++ b/src/templates/core/fetch/getRequestBody.hbs
@@ -3,7 +3,9 @@ function getRequestBody(options: ApiRequestOptions): BodyInit | undefined {
         return getFormData(options.formData);
     }
     if (options.body) {
-        if (isString(options.body) || isBlob(options.body)) {
+        if (options.bodyMediaType.includes('/json')) {
+            return JSON.stringify(options.body)
+        } else if (isString(options.body) || isBlob(options.body)) {
             return options.body;
         } else {
             return JSON.stringify(options.body);
diff --git a/src/templates/core/node/getHeaders.hbs b/src/templates/core/node/getHeaders.hbs
index 1052e40c..57021103 100644
--- a/src/templates/core/node/getHeaders.hbs
+++ b/src/templates/core/node/getHeaders.hbs
@@ -20,12 +20,16 @@ async function getHeaders(options: ApiRequestOptions): Promise<Headers> {
     }
 
     if (options.body) {
-        if (isBinary(options.body)) {
-            headers.append('Content-Type', 'application/octet-stream');
-        } else if (isString(options.body)) {
-            headers.append('Content-Type', 'text/plain');
+        if (options.bodyMediaType) {
+            headers.append('Content-Type', options.bodyMediaType);
         } else {
-            headers.append('Content-Type', 'application/json');
+            if (isBinary(options.body)) {
+                headers.append('Content-Type', 'application/octet-stream');
+            } else if (isString(options.body)) {
+                headers.append('Content-Type', 'text/plain');
+            } else {
+                headers.append('Content-Type', 'application/json');
+            }
         }
     }
     return headers;
diff --git a/src/templates/core/node/getRequestBody.hbs b/src/templates/core/node/getRequestBody.hbs
index 0977770c..97b148eb 100644
--- a/src/templates/core/node/getRequestBody.hbs
+++ b/src/templates/core/node/getRequestBody.hbs
@@ -3,7 +3,9 @@ function getRequestBody(options: ApiRequestOptions): BodyInit | undefined {
         return getFormData(options.formData);
     }
     if (options.body) {
-        if (isString(options.body) || isBinary(options.body)) {
+        if (options.bodyMediaType.includes('/json')) {
+            return JSON.stringify(options.body)
+        } else if (isString(options.body) || isBlob(options.body)) {
             return options.body;
         } else {
             return JSON.stringify(options.body);
diff --git a/src/templates/core/xhr/getHeaders.hbs b/src/templates/core/xhr/getHeaders.hbs
index 9b35a8b5..b4e6d1b2 100644
--- a/src/templates/core/xhr/getHeaders.hbs
+++ b/src/templates/core/xhr/getHeaders.hbs
@@ -20,12 +20,16 @@ async function getHeaders(options: ApiRequestOptions): Promise<Headers> {
     }
 
     if (options.body) {
-        if (isBlob(options.body)) {
-            headers.append('Content-Type', options.body.type || 'application/octet-stream');
-        } else if (isString(options.body)) {
-            headers.append('Content-Type', 'text/plain');
+        if (options.bodyMediaType) {
+            headers.append('Content-Type', options.bodyMediaType);
         } else {
-            headers.append('Content-Type', 'application/json');
+            if (isBlob(options.body)) {
+                headers.append('Content-Type', options.body.type || 'application/octet-stream');
+            } else if (isString(options.body)) {
+                headers.append('Content-Type', 'text/plain');
+            } else {
+                headers.append('Content-Type', 'application/json');
+            }
         }
     }
     return headers;
diff --git a/src/templates/core/xhr/getRequestBody.hbs b/src/templates/core/xhr/getRequestBody.hbs
index 33ec6249..19d6bc51 100644
--- a/src/templates/core/xhr/getRequestBody.hbs
+++ b/src/templates/core/xhr/getRequestBody.hbs
@@ -3,7 +3,9 @@ function getRequestBody(options: ApiRequestOptions): any {
         return getFormData(options.formData);
     }
     if (options.body) {
-        if (isString(options.body) || isBlob(options.body)) {
+        if (options.bodyMediaType.includes('/json')) {
+            return JSON.stringify(options.body)
+        } else if (isString(options.body) || isBlob(options.body)) {
             return options.body;
         } else {
             return JSON.stringify(options.body);
diff --git a/src/templates/exportService.hbs b/src/templates/exportService.hbs
index 315640d9..6e29af60 100644
--- a/src/templates/exportService.hbs
+++ b/src/templates/exportService.hbs
@@ -69,6 +69,9 @@ export class {{{name}}} {
             {{/if}}
             {{#if parametersBody}}
             body: {{{parametersBody.name}}},
+            {{#if parametersBody.mediaType}}
+            bodyMediaType: '{{{parametersBody.mediaType}}}',
+            {{/if}}
             {{/if}}
             {{#if responseHeader}}
             responseHeader: '{{{responseHeader}}}',