diff --git a/README.md b/README.md
index b61da8b13..c858efd09 100644
--- a/README.md
+++ b/README.md
@@ -1072,7 +1072,9 @@ Defaults:
   removeAdditional: false,
   useDefaults:      false,
   coerceTypes:      false,
+  // strict mode options
   strictDefaults:   false,
+  strictKeywords:   false,
   // asynchronous validation options:
   transpile:        undefined, // requires ajv-async package
   // advanced options:
@@ -1154,10 +1156,18 @@ Defaults:
   - `false` (default) - no type coercion.
   - `true` - coerce scalar data types.
   - `"array"` - in addition to coercions between scalar types, coerce scalar data to an array with one element and vice versa (as required by the schema).
-- _strictDefaults_: specify behavior for ignored `default` keywords in schemas. Option values:
+
+
+##### Strict mode options
+
+- _strictDefaults_: report ignored `default` keywords in schemas. Option values:
   - `false` (default) - ignored defaults are not reported
   - `true` - if an ignored default is present, throw an error
   - `"log"` - if an ignored default is present, log warning
+- _strictKeywords_: report unknown keywords in schemas. Option values:
+  - `false` (default) - unknown keywords are not reported
+  - `true` - if an unknown keyword is present, throw an error
+  - `"log"` - if an unknown keyword is present, log warning
 
 
 ##### Asynchronous validation options
diff --git a/lib/compile/rules.js b/lib/compile/rules.js
index 66f196a93..08b25aeb9 100644
--- a/lib/compile/rules.js
+++ b/lib/compile/rules.js
@@ -20,7 +20,7 @@ module.exports = function rules() {
 
   var ALL = [ 'type', '$comment' ];
   var KEYWORDS = [
-    '$schema', '$id', 'id', '$data', 'title',
+    '$schema', '$id', 'id', '$data', '$async', 'title',
     'description', 'default', 'definitions',
     'examples', 'readOnly', 'writeOnly',
     'contentMediaType', 'contentEncoding',
diff --git a/lib/compile/util.js b/lib/compile/util.js
index 263891c33..0efa00111 100644
--- a/lib/compile/util.js
+++ b/lib/compile/util.js
@@ -17,6 +17,7 @@ module.exports = {
   finalCleanUpCode: finalCleanUpCode,
   schemaHasRules: schemaHasRules,
   schemaHasRulesExcept: schemaHasRulesExcept,
+  schemaUnknownRules: schemaUnknownRules,
   toQuotedString: toQuotedString,
   getPathExpr: getPathExpr,
   getPath: getPath,
@@ -183,6 +184,12 @@ function schemaHasRulesExcept(schema, rules, exceptKeyword) {
 }
 
 
+function schemaUnknownRules(schema, rules) {
+  if (typeof schema == 'boolean') return;
+  for (var key in schema) if (!rules[key]) return key;
+}
+
+
 function toQuotedString(str) {
   return '\'' + escapeQuotes(str) + '\'';
 }
diff --git a/lib/dot/validate.jst b/lib/dot/validate.jst
index 12a2fe494..3c92ef441 100644
--- a/lib/dot/validate.jst
+++ b/lib/dot/validate.jst
@@ -20,6 +20,17 @@
     , $id = it.self._getId(it.schema);
 }}
 
+{{
+  if (it.opts.strictKeywords) {
+    var $unknownKwd = it.util.schemaUnknownRules(it.schema, it.RULES.keywords);
+    if ($unknownKwd) {
+      var $keywordsMsg = 'unknown keyword: ' + $unknownKwd;
+      if (it.opts.strictKeywords === 'log') it.logger.warn($keywordsMsg);
+      else throw new Error($keywordsMsg);
+    }
+  }
+}}
+
 {{? it.isTop }}
   var validate = {{?$async}}{{it.async = true;}}async {{?}}function(data, dataPath, parentData, parentDataProperty, rootData) {
     'use strict';
diff --git a/spec/custom.spec.js b/spec/custom.spec.js
index 5b1b6f03a..2924fceea 100644
--- a/spec/custom.spec.js
+++ b/spec/custom.spec.js
@@ -415,6 +415,7 @@ describe('Custom keywords', function () {
     it('should correctly expand macros in macro expansions', function() {
       instances.forEach(function (_ajv) {
         _ajv.addKeyword('range', { type: 'number', macro: macroRange });
+        _ajv.addKeyword('exclusiveRange', { metaSchema: {type: 'boolean'} });
         _ajv.addKeyword('myContains', { type: 'array', macro: macroContains });
 
         var schema = {
@@ -811,6 +812,7 @@ describe('Custom keywords', function () {
   function testRangeKeyword(definition, customErrors, numErrors) {
     instances.forEach(function (_ajv) {
       _ajv.addKeyword('x-range', definition);
+      _ajv.addKeyword('exclusiveRange', {metaSchema: {type: 'boolean'}});
 
       var schema = { "x-range": [2, 4] };
       var validate = _ajv.compile(schema);
@@ -849,6 +851,7 @@ describe('Custom keywords', function () {
   function testMultipleRangeKeyword(definition, numErrors) {
     instances.forEach(function (_ajv) {
       _ajv.addKeyword('x-range', definition);
+      _ajv.addKeyword('exclusiveRange', {metaSchema: {type: 'boolean'}});
 
       var schema = {
         "properties": {
diff --git a/spec/options/strictKeywords.spec.js b/spec/options/strictKeywords.spec.js
new file mode 100644
index 000000000..b212d15c7
--- /dev/null
+++ b/spec/options/strictKeywords.spec.js
@@ -0,0 +1,66 @@
+'use strict';
+
+var Ajv = require('../ajv');
+var should = require('../chai').should();
+
+
+describe('strictKeywords option', function() {
+  describe('strictKeywords = false', function() {
+    it('should NOT throw an error or log a warning given an unknown keyword', function() {
+      var output = {};
+      var ajv = new Ajv({
+        strictKeywords: false,
+        logger: getLogger(output)
+      });
+      var schema = {
+        properties: {},
+        unknownKeyword: 1
+      };
+
+      ajv.compile(schema);
+      should.not.exist(output.warning);
+    });
+  });
+
+  describe('strictKeywords = true', function() {
+    it('should throw an error given an unknown keyword in the schema root when strictKeywords is true', function() {
+      var ajv = new Ajv({strictKeywords: true});
+      var schema = {
+        properties: {},
+        unknownKeyword: 1
+      };
+      should.throw(function() { ajv.compile(schema); });
+    });
+  });
+
+  describe('strictKeywords = "log"', function() {
+    it('should log a warning given an unknown keyword in the schema root when strictKeywords is "log"', function() {
+      var output = {};
+      var ajv = new Ajv({
+        strictKeywords: 'log',
+        logger: getLogger(output)
+      });
+      var schema = {
+        properties: {},
+        unknownKeyword: 1
+      };
+      ajv.compile(schema);
+      should.equal(output.warning, 'unknown keyword: unknownKeyword');
+    });
+  });
+
+
+  function getLogger(output) {
+    return {
+      log: function() {
+        throw new Error('log should not be called');
+      },
+      warn: function(warning) {
+        output.warning = warning;
+      },
+      error: function() {
+        throw new Error('error should not be called');
+      }
+    };
+  }
+});