diff --git a/docs/general/fonts.md b/docs/general/fonts.md
index 9b2d6c842ce..df9f4f6cb67 100644
--- a/docs/general/fonts.md
+++ b/docs/general/fonts.md
@@ -29,7 +29,7 @@ let chart = new Chart(ctx, {
 | `family` | `string` | `"'Helvetica Neue', 'Helvetica', 'Arial', sans-serif"` | Default font family for all text, follows CSS font-family options.
 | `size` | `number` | `12` | Default font size (in px) for text. Does not apply to radialLinear scale point labels.
 | `style` | `string` | `'normal'` | Default font style. Does not apply to tooltip title or footer. Does not apply to chart title. Follows CSS font-style options (i.e. normal, italic, oblique, initial, inherit).
-| `weight` | `string` | `undefined` | Default font weight (boldness). (see [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/font-weight)).
+| `weight` | `normal` \| `bold` \| `lighter` \| `bolder` \| `number` | `undefined` | Default font weight (boldness). (see [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/font-weight)).
 | `lineHeight` | `number`\|`string` | `1.2` | Height of an individual line of text (see [MDN](https://developer.mozilla.org/en-US/docs/Web/CSS/line-height)).
 
 ## Missing Fonts
diff --git a/src/types/index.d.ts b/src/types/index.d.ts
index 12a6ed6c1fa..6e661188a0b 100644
--- a/src/types/index.d.ts
+++ b/src/types/index.d.ts
@@ -1777,7 +1777,7 @@ export interface FontSpec {
   /**
    * Default font weight (boldness). (see MDN).
    */
-  weight: string | null;
+  weight: 'normal' | 'bold' | 'lighter' | 'bolder' | number | null;
   /**
    * Height of an individual line of text (see MDN).
    * @default 1.2