diff --git a/src/Format.js b/src/Format.js
index 2177808c7..9dac1a886 100644
--- a/src/Format.js
+++ b/src/Format.js
@@ -1,13 +1,28 @@
 import { isNone } from "./util.js";
 import Type from "./Type.js";
 
-let instance = Symbol("instance");
+// Type "imports"
+/** @typedef {import("./types.js").ColorSpace} ColorSpace */
+/** @typedef {import("./types.js").Format} FormatInterface */
+
+export const instance = Symbol("instance");
 
 /**
  * @class Format
  * Class to hold a color serialization format
  */
 export default class Format {
+	// Class properties - declared here so that type inference works
+	type;
+	name;
+	spaceCoords;
+	/** @type {[Type, Type, Type]} */
+	coords;
+
+	/**
+	 * @param {FormatInterface} format
+	 * @param {ColorSpace} space
+	 */
 	constructor (format, space = format.space) {
 		format[instance] = this;
 		this.type = "function";
diff --git a/src/Type.js b/src/Type.js
index 9a1164b2a..691342e97 100644
--- a/src/Type.js
+++ b/src/Type.js
@@ -1,6 +1,15 @@
 import { serializeNumber, mapRange } from "./util.js";
 
 export default class Type {
+	// Class properties - declared here so that type inference works
+	type;
+	coordMeta;
+	coordRange;
+
+	/**
+	 * @param {any} type
+	 * @param {import("./types.js").CoordMeta} coordMeta
+	 */
 	constructor (type, coordMeta) {
 		if (typeof type === "object") {
 			this.coordMeta = type;
@@ -49,7 +58,6 @@ export default class Type {
 	/**
 	 * Map a number to the internal representation
 	 * @param {number} number
-	 * @returns
 	 */
 	resolve (number) {
 		if (this.type === "<angle>") {
@@ -70,7 +78,6 @@ export default class Type {
 	 * Serialize a number from the internal representation to a string
 	 * @param {number} number
 	 * @param {number} [precision]
-	 * @returns
 	 */
 	serialize (number, precision) {
 		let toRange = this.type === "<percentage>" ? [-100, 100] : this.range;
diff --git a/src/space.d.ts b/src/space.d.ts
index c251303aa..26b97e055 100644
--- a/src/space.d.ts
+++ b/src/space.d.ts
@@ -5,6 +5,8 @@
  */
 import { White } from "./adapt.js";
 import { ColorConstructor, Coords, ColorTypes } from "./color.js";
+import type FormatClasa from "./Format.js";
+import type { instance } from "./Format.js";
 
 export interface Format {
 	/** @default "function" */
@@ -31,6 +33,7 @@ export interface Format {
 	 * Must be defined for a format to support serialization
 	 */
 	serialize?: ((coords: Coords, alpha: number, opts?: Record<string, any>) => string) | undefined;
+	[instance]?: FormatClass | undefined;
 }
 
 export interface CoordMeta {
diff --git a/src/types.d.ts b/src/types.d.ts
index 429ebca1e..3e5cf4bfa 100644
--- a/src/types.d.ts
+++ b/src/types.d.ts
@@ -118,6 +118,7 @@ export interface SerializeOptions {
 // space.js
 import type ColorSpace from "./space.js";
 import type { Format, Ref, SpaceOptions } from "./space.js";
+export type { ColorSpace };
 export type * from "./space.js";
 
 // toGamut.js