diff --git a/lib/afterRequest.json b/lib/afterRequest.json
index 5f52581..10f37d3 100644
--- a/lib/afterRequest.json
+++ b/lib/afterRequest.json
@@ -2,7 +2,6 @@
   "$id": "afterRequest.json#",
   "$schema": "http://json-schema.org/draft-06/schema#",
   "type": "object",
-  "optional": true,
   "required": [
     "lastAccess",
     "eTag",
diff --git a/lib/beforeRequest.json b/lib/beforeRequest.json
index c7b5c10..afad6d0 100644
--- a/lib/beforeRequest.json
+++ b/lib/beforeRequest.json
@@ -2,7 +2,6 @@
   "$id": "beforeRequest.json#",
   "$schema": "http://json-schema.org/draft-06/schema#",
   "type": "object",
-  "optional": true,
   "required": [
     "lastAccess",
     "eTag",
diff --git a/lib/entry.json b/lib/entry.json
index 18025f4..f6e0ead 100644
--- a/lib/entry.json
+++ b/lib/entry.json
@@ -2,7 +2,6 @@
   "$id": "entry.json#",
   "$schema": "http://json-schema.org/draft-06/schema#",
   "type": "object",
-  "optional": true,
   "required": [
     "startedDateTime",
     "time",
@@ -22,7 +21,7 @@
     },
     "time": {
       "type": "number",
-      "min": 0
+      "minimum": 0
     },
     "request": {
       "$ref": "request.json#"
@@ -37,10 +36,9 @@
       "$ref": "timings.json#"
     },
     "serverIPAddress": {
-      "type": "string",
       "oneOf": [
-        { "format": "ipv4" },
-        { "format": "ipv6" }
+        { "type": "string", "format": "ipv4" },
+        { "type": "string", "format": "ipv6" }
       ]
     },
     "connection": {
diff --git a/lib/index.js b/lib/index.js
index 244c08e..a92a39a 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -14,6 +14,7 @@ module.exports = {
   log: require('./log.json'),
   page: require('./page.json'),
   pageTimings: require('./pageTimings.json'),
+  param: require('./param.json'),
   postData: require('./postData.json'),
   query: require('./query.json'),
   request: require('./request.json'),
diff --git a/lib/page.json b/lib/page.json
index e24a3ce..963b561 100644
--- a/lib/page.json
+++ b/lib/page.json
@@ -2,7 +2,6 @@
   "$id": "page.json#",
   "$schema": "http://json-schema.org/draft-06/schema#",
   "type": "object",
-  "optional": true,
   "required": [
     "startedDateTime",
     "id",
@@ -16,8 +15,7 @@
       "pattern": "^(\\d{4})(-)?(\\d\\d)(-)?(\\d\\d)(T)?(\\d\\d)(:)?(\\d\\d)(:)?(\\d\\d)(\\.\\d+)?(Z|([+-])(\\d\\d)(:)?(\\d\\d))"
     },
     "id": {
-      "type": "string",
-      "unique": true
+      "type": "string"
     },
     "title": {
       "type": "string"
diff --git a/lib/pageTimings.json b/lib/pageTimings.json
index 130411f..3fe9b19 100644
--- a/lib/pageTimings.json
+++ b/lib/pageTimings.json
@@ -5,11 +5,11 @@
   "properties": {
     "onContentLoad": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "onLoad": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "comment": {
       "type": "string"
diff --git a/lib/param.json b/lib/param.json
new file mode 100644
index 0000000..22352dd
--- /dev/null
+++ b/lib/param.json
@@ -0,0 +1,25 @@
+{
+  "$id": "param.json#",
+  "$schema": "http://json-schema.org/draft-06/schema#",
+  "type": "object",
+  "required": [
+    "name"
+  ],
+  "properties": {
+    "name": {
+      "type": "string"
+    },
+    "value": {
+      "type": "string"
+    },
+    "fileName": {
+      "type": "string"
+    },
+    "contentType": {
+      "type": "string"
+    },
+    "comment": {
+      "type": "string"
+    }
+  }
+}
diff --git a/lib/postData.json b/lib/postData.json
index 3aa6294..f068ccb 100644
--- a/lib/postData.json
+++ b/lib/postData.json
@@ -2,7 +2,6 @@
   "$id": "postData.json#",
   "$schema": "http://json-schema.org/draft-06/schema#",
   "type": "object",
-  "optional": true,
   "required": [
     "mimeType"
   ],
@@ -15,25 +14,8 @@
     },
     "params": {
       "type": "array",
-      "required": [
-        "name"
-      ],
-      "properties": {
-        "name": {
-          "type": "string"
-        },
-        "value": {
-          "type": "string"
-        },
-        "fileName": {
-          "type": "string"
-        },
-        "contentType": {
-          "type": "string"
-        },
-        "comment": {
-          "type": "string"
-        }
+      "items": {
+        "$ref": "param.json#"
       }
     },
     "comment": {
diff --git a/lib/timings.json b/lib/timings.json
index 5fe7dc7..052dd4e 100644
--- a/lib/timings.json
+++ b/lib/timings.json
@@ -1,6 +1,7 @@
 {
   "$id": "timings.json#",
   "$schema": "http://json-schema.org/draft-06/schema#",
+  "type": "object",
   "required": [
     "send",
     "wait",
@@ -9,31 +10,31 @@
   "properties": {
     "dns": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "connect": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "blocked": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "send": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "wait": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "receive": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "ssl": {
       "type": "number",
-      "min": -1
+      "minimum": -1
     },
     "comment": {
       "type": "string"
diff --git a/package.json b/package.json
index 8064413..4beb010 100644
--- a/package.json
+++ b/package.json
@@ -43,7 +43,7 @@
     }
   },
   "devDependencies": {
-    "ajv": "^5.0.0",
+    "ajv": "^6.5.2",
     "codeclimate-test-reporter": "^0.4.0",
     "cz-conventional-changelog": "^1.2.0",
     "echint": "^2.1.0",
diff --git a/test/index.js b/test/index.js
index 7a1fcb8..069dbb9 100644
--- a/test/index.js
+++ b/test/index.js
@@ -6,6 +6,9 @@ const tap = require('tap')
 
 tap.test('har-schema', (assert) => {
   const ajv = new Ajv()
+  const metaSchema = require('ajv/lib/refs/json-schema-draft-06.json')
+  metaSchema.additionalProperties = false
+  ajv.addMetaSchema(metaSchema)
   const keys = Object.keys(schemas)
 
   assert.plan(keys.length * 2)