diff --git a/package-lock.json b/package-lock.json
index 17a6e90..8d12ff5 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -18,14 +18,6 @@
         "@tsconfig/node22": "^22.0.2"
       }
     },
-    "node_modules/@openapi-ts/backend": {
-      "resolved": "packages/lib",
-      "link": true
-    },
-    "node_modules/@openapi-ts/cli": {
-      "resolved": "packages/cli",
-      "link": true
-    },
     "node_modules/@apidevtools/json-schema-ref-parser": {
       "version": "11.9.3",
       "license": "MIT",
@@ -1199,6 +1191,14 @@
         "node": ">= 8"
       }
     },
+    "node_modules/@openapi-ts/backend": {
+      "resolved": "packages/lib",
+      "link": true
+    },
+    "node_modules/@openapi-ts/cli": {
+      "resolved": "packages/cli",
+      "link": true
+    },
     "node_modules/@openapi-ts/request-types": {
       "version": "1.1.0",
       "dev": true,
@@ -5261,7 +5261,7 @@
       "name": "@openapi-ts/cli",
       "version": "3.0.1",
       "dependencies": {
-        "openapi-typescript": "^7.9.1"
+        "openapi-typescript": "https://github.com/luqasn/openapi-typescript/releases/download/v7.11.1-preview/openapi-typescript-7.11.1-preview.tgz"
       },
       "bin": {
         "openapi-ts-backend": "dist/cli.js"
@@ -5270,6 +5270,38 @@
         "typescript": "^5.9.3"
       }
     },
+    "packages/cli/node_modules/openapi-typescript": {
+      "version": "7.11.1-preview",
+      "resolved": "https://github.com/luqasn/openapi-typescript/releases/download/v7.11.1-preview/openapi-typescript-7.11.1-preview.tgz",
+      "integrity": "sha512-ktv+A9S0BzoGft4ugze1OAUFFwGg16ls1/ykdLfp0UZIckeTXmdW82G90ENg6EnhfiyMlnG9y6Uqo6SJ3f9D3A==",
+      "license": "MIT",
+      "dependencies": {
+        "@redocly/openapi-core": "^1.34.5",
+        "ansi-colors": "^4.1.3",
+        "change-case": "^5.4.4",
+        "parse-json": "^8.3.0",
+        "supports-color": "^10.2.2",
+        "yargs-parser": "^21.1.1"
+      },
+      "bin": {
+        "openapi-typescript": "bin/cli.js"
+      },
+      "peerDependencies": {
+        "typescript": "^5.x"
+      }
+    },
+    "packages/cli/node_modules/supports-color": {
+      "version": "10.2.2",
+      "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-10.2.2.tgz",
+      "integrity": "sha512-SS+jx45GF1QjgEXQx4NJZV9ImqmO2NPz5FNsIHrsDjh2YsHnawpan7SNQ1o8NuhrbHZy9AZhIoCUiCeaW/C80g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/chalk/supports-color?sponsor=1"
+      }
+    },
     "packages/lib": {
       "name": "@openapi-ts/backend",
       "version": "3.0.1",
diff --git a/packages/cli/package.json b/packages/cli/package.json
index d423f20..a07d792 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -10,7 +10,7 @@
     "postbuild": "chmod u+x dist/cli.js"
   },
   "dependencies": {
-    "openapi-typescript": "^7.9.1"
+    "openapi-typescript": "https://github.com/luqasn/openapi-typescript/releases/download/v7.11.1-preview/openapi-typescript-7.11.1-preview.tgz"
   },
   "peerDependencies": {
     "typescript": "^5.9.3"
diff --git a/packages/cli/src/typegen/typegen.ts b/packages/cli/src/typegen/typegen.ts
index ac74c84..db27b4c 100644
--- a/packages/cli/src/typegen/typegen.ts
+++ b/packages/cli/src/typegen/typegen.ts
@@ -17,7 +17,10 @@ function write(dirName: string, fileName: string, data: string) {
 async function createSpecTypes(specPath: string, outputDir: string) {
   const absolutePath = path.resolve(specPath);
   const url = pathToFileURL(absolutePath)
-  const ast = await openapiTS(url);
+
+  const ast = await openapiTS(url, {
+      makeParametersWithDefaultNotUndefined: true
+  });
   const ts = astToString(ast);
 
   return write(outputDir, 'spec.ts', ts);
diff --git a/packages/lib/src/openapi.ts b/packages/lib/src/openapi.ts
index 945e287..cba56aa 100644
--- a/packages/lib/src/openapi.ts
+++ b/packages/lib/src/openapi.ts
@@ -137,16 +137,34 @@ export class OpenApi<T> {
     return api;
   }
 
+  protected injectDefaults(parsed: Params, parameterMap: Record<string, OpenAPIV3_1.ParameterBaseObject>): Params {
+    for (const [name, p] of Object.entries(parameterMap)) {
+      if (p.schema === undefined) {
+          continue
+      }
+      if ("$ref" in p.schema) {
+          throw new Error('this should never happen, schema should be dereferenced by openapi-backend')
+      }
+      if (p.schema.default !== undefined && parsed[name] === undefined) {
+          parsed[name] = p.schema.default
+      }
+    }
+    return parsed;
+  }
+
   protected parseParams(rawParams: StringParams,
                         operation: OpenAPI.Operation,
                         type: ParameterType,
                         errors: Ajv.ErrorObject[]): Params {
+    const parameterMap = getParameterMap(operation, type)
     // This is mostly used to coerce types, which openapi-backend does internally but then throws away
-    return matchSchema<StringParams, Params>(
+    const parsed = matchSchema<StringParams, Params>(
         this.paramValidator,
         rawParams,
-        getParametersSchema(getParameterMap(operation, type)),
+        getParametersSchema(parameterMap),
         errors);
+
+    return this.injectDefaults(parsed, parameterMap)
   }
 
   protected parseRequest(apiContext: OpenAPI.Context): Request {
diff --git a/packages/test/api.yml b/packages/test/api.yml
index 312dd91..ace7cc5 100644
--- a/packages/test/api.yml
+++ b/packages/test/api.yml
@@ -20,6 +20,7 @@ components:
   schemas:
     Title:
       type: string
+      default: Mrs
       enum:
         - Mr
         - Mrs
diff --git a/packages/test/src/openapi.test.ts b/packages/test/src/openapi.test.ts
index c822293..1f059d4 100644
--- a/packages/test/src/openapi.test.ts
+++ b/packages/test/src/openapi.test.ts
@@ -11,7 +11,7 @@ function getTypeMap(obj: any) {
 
 const operations: OperationHandlers<unknown> = {
   greet: req => {
-    const {params: {name}, query: {title = ''}} = req;
+    const {params: {name}, query: {title}} = req;
 
     return {
       message: greet(title, name),
@@ -61,6 +61,19 @@ describe('API tests', () => {
       }
     });
     expect(res.statusCode).toEqual(200);
+    expect(res.body).toEqual({message: 'Hello, Mr John Doe'})
+  });
+
+  it('Should set default values for parameters automatically', async () => {
+      const res = await api.handleRequest({
+          method: 'GET',
+          path: '/greet/Jane%20Doe',
+          headers: {
+              authorization: 'true',
+          }
+      });
+      expect(res.statusCode).toEqual(200);
+      expect(res.body).toEqual({message: 'Hello, Mrs Jane Doe'})
   });
 
   it('Should handle a valid request with implicit status 201', async () => {