diff --git a/.gitignore b/.gitignore
index 287fdb8f83..2ec3d77b21 100644
--- a/.gitignore
+++ b/.gitignore
@@ -59,3 +59,6 @@ My Document.docx
 
 # Temporary folder
 tmp
+
+# Exclude Mac .DS_Store files
+.DS_Store
diff --git a/src/file/paragraph/run/properties.ts b/src/file/paragraph/run/properties.ts
index 41ca650995..93ab96cfa4 100644
--- a/src/file/paragraph/run/properties.ts
+++ b/src/file/paragraph/run/properties.ts
@@ -1,3 +1,4 @@
+// https://www.ecma-international.org/wp-content/uploads/ECMA-376-1_5th_edition_december_2016.zip page 297, section 17.3.2.21
 import { BorderElement, IBorderOptions } from "@file/border";
 import { IShadingAttributesProperties, Shading } from "@file/shading";
 import { ChangeAttributes, IChangedAttributesProperties } from "@file/track-revision/track-revision";
@@ -34,6 +35,7 @@ export enum TextEffect {
 }
 
 export interface IRunStylePropertiesOptions {
+    readonly noProof?: boolean;
     readonly bold?: boolean;
     readonly boldComplexScript?: boolean;
     readonly italics?: boolean;
@@ -131,7 +133,9 @@ export class RunProperties extends IgnoreIfEmptyXmlComponent {
         if (!options) {
             return;
         }
-
+        if (options.noProof !== undefined) {
+            this.push(new OnOffElement("w:noProof", options.noProof));
+        }
         if (options.bold !== undefined) {
             this.push(new OnOffElement("w:b", options.bold));
         }
diff --git a/src/file/paragraph/run/run.spec.ts b/src/file/paragraph/run/run.spec.ts
index b2027c2cfb..162804b5ba 100644
--- a/src/file/paragraph/run/run.spec.ts
+++ b/src/file/paragraph/run/run.spec.ts
@@ -8,8 +8,23 @@ import { EmphasisMarkType } from "./emphasis-mark";
 import { PageNumber, Run } from "./run";
 import { UnderlineType } from "./underline";
 import { TextEffect } from "./properties";
-
 describe("Run", () => {
+    describe("#noProof()", () => {
+        it("turns off spelling and grammar checkers for a run", () => {
+            const run = new Run({
+                noProof: true,
+            });
+            const tree = new Formatter().format(run);
+            expect(tree).to.deep.equal({
+                "w:r": [
+                    {
+                        "w:rPr": [{ "w:noProof": {} }],
+                    },
+                ],
+            });
+        });
+    });
+
     describe("#bold()", () => {
         it("it should add bold to the properties", () => {
             const run = new Run({