diff --git a/types/convict/convict-tests.ts b/types/convict/convict-tests.ts
index a61c27bdad..0451954ca1 100644
--- a/types/convict/convict-tests.ts
+++ b/types/convict/convict-tests.ts
@@ -105,6 +105,18 @@ conf.loadFile(['./configs/always.json', './configs/sometimes.json']);
 // perform validation
 
 conf.validate({ strict: true });
+conf.validate({ allowed: 'strict' });
+conf.validate({ allowed: 'warn' });
+
+// Chaining
+
+conf
+  .loadFile(['./configs/always.json', './configs/sometimes.json'])
+  .loadFile('./config/' + env + '.json')
+  .load({ jsonKey: 'jsonValue' })
+  .set('key', 'value')
+  .validate({ allowed: 'warn' })
+  .toString();
 
 var port: number = conf.default('port');
 
diff --git a/types/convict/index.d.ts b/types/convict/index.d.ts
index 981bc8148b..ebe5d21490 100644
--- a/types/convict/index.d.ts
+++ b/types/convict/index.d.ts
@@ -1,11 +1,26 @@
-// Type definitions for node-convict v0.6.0
+// Type definitions for node-convict v3.0.0
 // Project: https://github.com/mozilla/node-convict
-// Definitions by: Wim Looman <https://github.com/Nemo157>
+// Definitions by: Wim Looman <https://github.com/Nemo157>, Vesa Poikajärvi <https://github.com/vesse>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
 
 declare namespace convict {
 
+    type ValidationMethod = 'strict' | 'warn';
+
+    interface ValidateOptions {
+        /**
+         * If set to warn, any properties specified in config files that are not declared in
+         * the schema will print a warning. This is the default behavior. If set to strict,
+         * any properties specified in config files that are not declared in the schema will
+         * throw errors. This is to ensure that the schema and the config files are in sync.
+         */
+        allowed?: ValidationMethod;
+
+        /** @deprecated use allowed instead */
+        strict?: boolean;
+    }
+
     interface Format {
         name?: string;
         validate?: (val: any) => void;
@@ -34,14 +49,52 @@ declare namespace convict {
     }
 
     interface Config {
+        /**
+         * @returns the current value of the name property. name can use dot
+         * notation to reference nested values
+         */
         get(name: string): any;
+        /**
+         * @returns the default value of the name property. name can use dot
+         * notation to reference nested values
+         */
         default(name: string): any;
+        /**
+         * @returns true if the property name is defined, or false otherwise
+         */
         has(name: string): boolean;
-        set(name: string, value: any): void;
-        load(conf: Object): void;
-        loadFile(file: string): void;
-        loadFile(files: string[]): void;
-        validate(options?: { strict?: boolean }): void;
+        /**
+         * Sets the value of name to value. name can use dot notation to reference
+         * nested values, e.g. "database.port". If objects in the chain don't yet
+         * exist, they will be initialized to empty objects
+         *
+         * @return {Config} instance
+         */
+        set(name: string, value: any): Config;
+        /**
+         * Loads and merges a JavaScript object into config
+         *
+         * @return {Config} instance
+         */
+        load(conf: Object): Config;
+        /**
+         * Loads and merges one JSON configuration file into config
+         *
+         * @return {Config} instance
+         */
+        loadFile(file: string): Config;
+        /**
+         * Loads and merges multiple JSON configuration files into config
+         *
+         * @return {Config} instance
+         */
+        loadFile(files: string[]): Config;
+        /**
+         * Validates config against the schema used to initialize it
+         *
+         * @param options
+         */
+        validate(options?: ValidateOptions): Config;
         /**
          * Exports all the properties (that is the keys and their current values) as a {JSON} {Object}
          * @returns {Object} A {JSON} compliant {Object}