diff --git a/spec/modifiers/deepPartial.spec.ts b/spec/modifiers/deepPartial.spec.ts
new file mode 100644
index 0000000..9871c78
--- /dev/null
+++ b/spec/modifiers/deepPartial.spec.ts
@@ -0,0 +1,109 @@
+import { z } from 'zod';
+import { expectSchema, generateDataForRoute } from '../lib/helpers';
+
+describe('describe', () => {
+  it('generates a deepPartial object', () => {
+    const schema = z.object({
+      a: z.string(),
+      b: z.number(),
+    });
+
+    const { requestBody } = generateDataForRoute({
+      request: {
+        body: {
+          description: 'Test description',
+          required: true,
+          content: {
+            'application/json': {
+              schema: schema.deepPartial(),
+            },
+          },
+        },
+      },
+    });
+
+    expect(requestBody).toEqual({
+      description: 'Test description',
+      required: true,
+      content: {
+        'application/json': {
+          schema: {
+            type: 'object',
+            properties: {
+              a: { type: 'string' },
+              b: { type: 'number' },
+            },
+          },
+        },
+      },
+    });
+  });
+
+  it('generates a deepPartial object from a registered schema', () => {
+    const schema = z
+      .object({
+        a: z.string(),
+        b: z.number(),
+      })
+      .openapi('TestSchema');
+
+    const { documentSchemas, requestBody, responses } = generateDataForRoute({
+      request: {
+        body: {
+          description: 'Test description',
+          required: true,
+          content: {
+            'application/json': {
+              schema: schema.deepPartial(),
+            },
+          },
+        },
+      },
+      responses: {
+        200: {
+          description: 'Response description',
+          content: {
+            'application/json': { schema },
+          },
+        },
+      },
+    });
+
+    // The schema is registered
+    expect(documentSchemas).toEqual({
+      TestSchema: {
+        type: 'object',
+        properties: {
+          a: { type: 'string' },
+          b: { type: 'number' },
+        },
+        required: ['a', 'b'],
+      },
+    });
+
+    expect(responses[200]).toEqual({
+      description: 'Response description',
+      content: {
+        'application/json': {
+          schema: { $ref: '#/components/schemas/TestSchema' },
+        },
+      },
+    });
+
+    expect(requestBody).toEqual({
+      description: 'Test description',
+      required: true,
+      content: {
+        'application/json': {
+          schema: {
+            type: 'object',
+            properties: {
+              a: { type: 'string' },
+              b: { type: 'number' },
+            },
+          },
+        },
+      },
+    });
+  });
+});
diff --git a/src/zod-extensions.ts b/src/zod-extensions.ts
index 210728c..65aac7a 100644
--- a/src/zod-extensions.ts
+++ b/src/zod-extensions.ts
@@ -160,6 +160,8 @@ export function extendZodWithOpenApi(zod: typeof z) {
       value._def.openapi = initialShape[key]?._def?.openapi;
     });
 
+    result._def.openapi = undefined;
+
     return result;
   };