diff --git a/types/natural/index.d.ts b/types/natural/index.d.ts
index 3615a50fce..255d8d4dca 100644
--- a/types/natural/index.d.ts
+++ b/types/natural/index.d.ts
@@ -202,3 +202,40 @@ declare class Spellcheck {
     isCorrect(word: string): boolean;
     getCorrections(word: string, maxDistance?: number): string[];
 }
+
+declare class Predicate {
+    constructor(name: string, parameter1: string, parameter2?: string);
+    name: string;
+    parameter1: string;
+    parameter2?: string;
+    function?: (tagged_sentence: string[][], i: number, parameter: string) => boolean;
+    evaluate(tagged_sentence: string[][], position: number): boolean;
+}
+
+declare class TransformationRule {
+    constructor(c1: string, c2: string, predicate: string, parameter1: string, parameter2?: string);
+    literal: string[];
+    predicate: Predicate;
+    old_category: string;
+    new_category: string;
+    apply(tagged_sentence: string[][], position: number): void;
+}
+
+declare class RuleSet {
+    constructor(filename: string);
+    rules: TransformationRule[];
+}
+
+declare class Lexicon {
+    constructor(filename: string, defaultCategory: string);
+    defaultCategory: string;
+    parseLexicon(data: string): void;
+    tagWord(word: string): string[];
+}
+
+declare class BrillPOSTagger {
+    constructor(lexicon: Lexicon, ruleSet: RuleSet);
+    lexicon: Lexicon;
+    ruleSet: RuleSet;
+    tag(sentence: string[]): string[][];
+}
diff --git a/types/natural/natural-tests.ts b/types/natural/natural-tests.ts
index c8650c6308..f994928f80 100644
--- a/types/natural/natural-tests.ts
+++ b/types/natural/natural-tests.ts
@@ -259,3 +259,16 @@ var spellcheck = new natural.Spellcheck(corpus);
 spellcheck.isCorrect('cat'); // false
 spellcheck.getCorrections('soemthing', 1); // ['something']
 spellcheck.getCorrections('soemthing', 2); // ['something', 'soothing']
+
+// POS Tagger
+
+var rulesFilename = 'fileName';
+var lexiconFilename = 'fileName';
+var defaultCategory = 'N';
+
+var lexicon = new natural.Lexicon(lexiconFilename, defaultCategory);
+var rules = new natural.RuleSet(rulesFilename);
+var tagger = new natural.BrillPOSTagger(lexicon, rules);
+
+var sentence = ["I", "see", "the", "man", "with", "the", "telescope"];
+tagger.tag(sentence);