diff --git a/package-lock.json b/package-lock.json
index 9609041f..40bad9fe 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,7 +9,7 @@
       "version": "1.11.4",
       "license": "MIT",
       "dependencies": {
-        "ajv": "^8.17.1",
+        "ajv": "^6.12.6",
         "content-type": "^1.0.5",
         "cors": "^2.8.5",
         "cross-spawn": "^7.0.5",
@@ -1036,30 +1036,6 @@
         "url": "https://opencollective.com/eslint"
       }
     },
-    "node_modules/@eslint/eslintrc/node_modules/ajv": {
-      "version": "6.12.6",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
-      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "fast-deep-equal": "^3.1.1",
-        "fast-json-stable-stringify": "^2.0.0",
-        "json-schema-traverse": "^0.4.1",
-        "uri-js": "^4.2.2"
-      },
-      "funding": {
-        "type": "github",
-        "url": "https://github.com/sponsors/epoberezkin"
-      }
-    },
-    "node_modules/@eslint/eslintrc/node_modules/json-schema-traverse": {
-      "version": "0.4.1",
-      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz",
-      "integrity": "sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/@eslint/js": {
       "version": "9.13.0",
       "resolved": "https://registry.npmjs.org/@eslint/js/-/js-9.13.0.tgz",
@@ -2223,15 +2199,15 @@
       }
     },
     "node_modules/ajv": {
-      "version": "8.17.1",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-8.17.1.tgz",
-      "integrity": "sha512-B/gBuNg5SiMTrPkC+A2+cW0RszwxYmn6VYxB/inlBStS5nx6xHIt/ehKRhIMhqusl7a8LjQoZnjCs5vhwxOQ1g==",
+      "version": "6.12.6",
+      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
+      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
       "license": "MIT",
       "dependencies": {
-        "fast-deep-equal": "^3.1.3",
-        "fast-uri": "^3.0.1",
-        "json-schema-traverse": "^1.0.0",
-        "require-from-string": "^2.0.2"
+        "fast-deep-equal": "^3.1.1",
+        "fast-json-stable-stringify": "^2.0.0",
+        "json-schema-traverse": "^0.4.1",
+        "uri-js": "^4.2.2"
       },
       "funding": {
         "type": "github",
@@ -3241,30 +3217,6 @@
         "url": "https://opencollective.com/eslint"
       }
     },
-    "node_modules/eslint/node_modules/ajv": {
-      "version": "6.12.6",
-      "resolved": "https://registry.npmjs.org/ajv/-/ajv-6.12.6.tgz",
-      "integrity": "sha512-j3fVLgvTo527anyYyJOGTYJbG+vnnQYvE0m5mmkc1TK+nxAppkCLMIL0aZ4dblVCNoGShhm+kzE4ZUykBoMg4g==",
-      "dev": true,
-      "license": "MIT",
-      "dependencies": {
-        "fast-deep-equal": "^3.1.1",
-        "fast-json-stable-stringify": "^2.0.0",
-        "json-schema-traverse": "^0.4.1",
-        "uri-js": "^4.2.2"
-      },
-      "funding": {
-        "type": "github",
-        "url": "https://github.com/sponsors/epoberezkin"
-      }
-    },
-    "node_modules/eslint/node_modules/json-schema-traverse": {
-      "version": "0.4.1",
-      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz",
-      "integrity": "sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg==",
-      "dev": true,
-      "license": "MIT"
-    },
     "node_modules/espree": {
       "version": "10.2.0",
       "resolved": "https://registry.npmjs.org/espree/-/espree-10.2.0.tgz",
@@ -3532,8 +3484,7 @@
     "node_modules/fast-json-stable-stringify": {
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/fast-json-stable-stringify/-/fast-json-stable-stringify-2.1.0.tgz",
-      "integrity": "sha512-lhd/wF+Lk98HZoTCtlVraHtfh5XYijIjalXck7saUtuanSDyLMxnHhSXEDJqHxD7msR8D0uCmqlkwjCV8xvwHw==",
-      "dev": true
+      "integrity": "sha512-lhd/wF+Lk98HZoTCtlVraHtfh5XYijIjalXck7saUtuanSDyLMxnHhSXEDJqHxD7msR8D0uCmqlkwjCV8xvwHw=="
     },
     "node_modules/fast-levenshtein": {
       "version": "2.0.6",
@@ -3548,22 +3499,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/fast-uri": {
-      "version": "3.0.6",
-      "resolved": "https://registry.npmjs.org/fast-uri/-/fast-uri-3.0.6.tgz",
-      "integrity": "sha512-Atfo14OibSv5wAp4VWNsFYE1AchQRTv9cBGWET4pZWHzYshFSS9NQI6I57rdKn9croWVMbYFbLhJ+yJvmZIIHw==",
-      "funding": [
-        {
-          "type": "github",
-          "url": "https://github.com/sponsors/fastify"
-        },
-        {
-          "type": "opencollective",
-          "url": "https://opencollective.com/fastify"
-        }
-      ],
-      "license": "BSD-3-Clause"
-    },
     "node_modules/fastq": {
       "version": "1.17.1",
       "resolved": "https://registry.npmjs.org/fastq/-/fastq-1.17.1.tgz",
@@ -4944,9 +4879,9 @@
       "dev": true
     },
     "node_modules/json-schema-traverse": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-1.0.0.tgz",
-      "integrity": "sha512-NM8/P9n3XjXhIZn1lLhkFaACTOURQXjWhV4BA/RnOv8xvgqtqpAX9IO4mRQxSx1Rlo4tqzeqb0sOlruaOy3dug==",
+      "version": "0.4.1",
+      "resolved": "https://registry.npmjs.org/json-schema-traverse/-/json-schema-traverse-0.4.1.tgz",
+      "integrity": "sha512-xbbCH5dCYU5T8LcEhhuh7HJ88HXuW3qsI3Y0zOZFKfZEHcpWiHU/Jxzk629Brsab/mMiHQti9wMP+845RPe3Vg==",
       "license": "MIT"
     },
     "node_modules/json-stable-stringify-without-jsonify": {
@@ -5621,7 +5556,6 @@
       "version": "2.3.1",
       "resolved": "https://registry.npmjs.org/punycode/-/punycode-2.3.1.tgz",
       "integrity": "sha512-vYt7UD1U9Wg6138shLtLOvdAu+8DsC/ilFtEVHcH+wydcSpNE20AfSOduf6MkRFahL5FY7X1oU7nKVZFtfq8Fg==",
-      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=6"
@@ -5727,15 +5661,6 @@
         "node": ">=0.10.0"
       }
     },
-    "node_modules/require-from-string": {
-      "version": "2.0.2",
-      "resolved": "https://registry.npmjs.org/require-from-string/-/require-from-string-2.0.2.tgz",
-      "integrity": "sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=0.10.0"
-      }
-    },
     "node_modules/resolve": {
       "version": "1.22.8",
       "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.22.8.tgz",
@@ -6518,7 +6443,6 @@
       "version": "4.4.1",
       "resolved": "https://registry.npmjs.org/uri-js/-/uri-js-4.4.1.tgz",
       "integrity": "sha512-7rKUyy33Q1yc98pQ1DAmLtwX109F7TIfWlW1Ydo8Wl1ii1SeHieeh0HHfPeL2fMXK6z0s8ecKs9frCuLJvndBg==",
-      "dev": true,
       "license": "BSD-2-Clause",
       "dependencies": {
         "punycode": "^2.1.0"
diff --git a/package.json b/package.json
index 69445c34..c33cad94 100644
--- a/package.json
+++ b/package.json
@@ -46,7 +46,7 @@
     "client": "tsx src/cli.ts client"
   },
   "dependencies": {
-    "ajv": "^8.17.1",
+    "ajv": "^6.12.6",
     "content-type": "^1.0.5",
     "cors": "^2.8.5",
     "cross-spawn": "^7.0.5",
diff --git a/src/client/index.ts b/src/client/index.ts
index 70870633..98618a17 100644
--- a/src/client/index.ts
+++ b/src/client/index.ts
@@ -43,7 +43,8 @@ import {
   ErrorCode,
   McpError,
 } from "../types.js";
-import { Ajv, type ValidateFunction } from "ajv";
+import Ajv from "ajv";
+import type { ValidateFunction } from "ajv";
 
 export type ClientOptions = ProtocolOptions & {
   /**
@@ -102,7 +103,7 @@ export class Client<
   ) {
     super(options);
     this._capabilities = options?.capabilities ?? {};
-    this._ajv = new Ajv({ strict: false, validateFormats: true });
+    this._ajv = new Ajv();
   }
 
   /**