diff --git a/package.json b/package.json
index b82b55a..a2756cf 100644
--- a/package.json
+++ b/package.json
@@ -18,6 +18,7 @@
 	],
 	"types": "./types/index.d.ts",
 	"devDependencies": {
+		"@js-temporal/polyfill": "^0.5.1",
 		"dts-buddy": "^0.0.4",
 		"publint": "^0.1.7",
 		"typescript": "^3.1.3",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 07e4699..e2212ec 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -1,6 +1,9 @@
 lockfileVersion: '6.0'
 
 devDependencies:
+  '@js-temporal/polyfill':
+    specifier: ^0.5.1
+    version: 0.5.1
   dts-buddy:
     specifier: ^0.0.4
     version: 0.0.4
@@ -57,6 +60,13 @@ packages:
       '@jridgewell/sourcemap-codec': 1.4.14
     dev: true
 
+  /@js-temporal/polyfill@0.5.1:
+    resolution: {integrity: sha512-hloP58zRVCRSpgDxmqCWJNlizAlUgJFqG2ypq79DCvyv9tHjRYMDOcPFjzfl/A1/YxDvRCZz8wvZvmapQnKwFQ==}
+    engines: {node: '>=12'}
+    dependencies:
+      jsbi: 4.3.2
+    dev: true
+
   /balanced-match@1.0.2:
     resolution: {integrity: sha512-3oSeUO0TMV67hN1AmbXsK4yaqU7tjiHlbxRDZOpH0KW9+CeX4bRAaX0Anxt0tx2MrpRpWwQaPwIlISEJhYU5Pw==}
     dev: true
@@ -133,6 +143,10 @@ packages:
     resolution: {integrity: sha512-k/vGaX4/Yla3WzyMCvTQOXYeIHvqOKtnqBduzTHpzpQZzAskKMhZ2K+EnBiSM9zGSoIFeMpXKxa4dYeZIQqewQ==}
     dev: true
 
+  /jsbi@4.3.2:
+    resolution: {integrity: sha512-9fqMSQbhJykSeii05nxKl4m6Eqn2P6rOlYiS+C5Dr/HPIU/7yZxu5qzbs40tgaFORiw2Amd0mirjxatXYMkIew==}
+    dev: true
+
   /kleur@4.1.5:
     resolution: {integrity: sha512-o+NO+8WrRiQEE4/7nwRJhN1HWpVmJm511pBHUxPLtp0BUISzlBplORYSmTclCnJvQq2tKu/sgl3xVpkc7ZWuQQ==}
     engines: {node: '>=6'}
diff --git a/src/parse.js b/src/parse.js
index f0fe2c1..fe1fd09 100644
--- a/src/parse.js
+++ b/src/parse.js
@@ -128,6 +128,20 @@ export function unflatten(parsed, revivers) {
             break;
           }
 
+					case 'Temporal.Duration':
+					case 'Temporal.Instant':
+					case 'Temporal.PlainDate':
+					case 'Temporal.PlainTime':
+					case 'Temporal.PlainDateTime':
+					case 'Temporal.PlainMonthDay':
+					case 'Temporal.PlainYearMonth':
+					case 'Temporal.ZonedDateTime': {
+						const temporalName = type.slice(9);
+						// @ts-expect-error TS doesn't know about Temporal yet
+						hydrated[index] = Temporal[temporalName].from(value[1]);
+						break;
+					}
+
 					default:
 						throw new Error(`Unknown type ${type}`);
 				}
diff --git a/src/stringify.js b/src/stringify.js
index df291fd..ce040c0 100644
--- a/src/stringify.js
+++ b/src/stringify.js
@@ -166,7 +166,18 @@ export function stringify(value, reducers) {
 					str = `["ArrayBuffer","${base64}"]`;
 					break;
 				}
-				
+
+				case 'Temporal.Duration':
+				case 'Temporal.Instant':
+				case 'Temporal.PlainDate':
+				case 'Temporal.PlainTime':
+				case 'Temporal.PlainDateTime':
+				case 'Temporal.PlainMonthDay':
+				case 'Temporal.PlainYearMonth':
+				case 'Temporal.ZonedDateTime':
+					str = `["${type}",${stringify_string(thing.toString())}]`;
+					break;
+
 				default:
 					if (!is_plain_object(thing)) {
 						throw new DevalueError(
diff --git a/src/uneval.js b/src/uneval.js
index ce3ef34..131f46a 100644
--- a/src/uneval.js
+++ b/src/uneval.js
@@ -99,6 +99,16 @@ export function uneval(value, replacer) {
 				case "ArrayBuffer":
 					return;
 
+				case 'Temporal.Duration':
+				case 'Temporal.Instant':
+				case 'Temporal.PlainDate':
+				case 'Temporal.PlainTime':
+				case 'Temporal.PlainDateTime':
+				case 'Temporal.PlainMonthDay':
+				case 'Temporal.PlainYearMonth':
+				case 'Temporal.ZonedDateTime':
+					return;
+
 				default:
 					if (!is_plain_object(thing)) {
 						throw new DevalueError(
@@ -199,6 +209,16 @@ export function uneval(value, replacer) {
 				return `new Uint8Array([${ui8.toString()}]).buffer`;
 			}
 
+			case 'Temporal.Duration':
+			case 'Temporal.Instant':
+			case 'Temporal.PlainDate':
+			case 'Temporal.PlainTime':
+			case 'Temporal.PlainDateTime':
+			case 'Temporal.PlainMonthDay':
+			case 'Temporal.PlainYearMonth':
+			case 'Temporal.ZonedDateTime':
+				return `${type}.from(${stringify_string(thing.toString())})`;
+
 			default:
 				const obj = `{${Object.keys(thing)
 					.map((key) => `${safe_key(key)}:${stringify(thing[key])}`)
diff --git a/test/test.js b/test/test.js
index ebd4147..f1a5f2a 100644
--- a/test/test.js
+++ b/test/test.js
@@ -3,6 +3,11 @@ import * as assert from 'uvu/assert';
 import * as uvu from 'uvu';
 import { uneval, unflatten, parse, stringify } from '../index.js';
 
+import { Temporal } from '@js-temporal/polyfill'
+if (!globalThis.Temporal) {
+	globalThis.Temporal = Temporal;
+}
+
 class Custom {
 	constructor(value) {
 		this.value = value;
@@ -171,6 +176,61 @@ const fixtures = {
 			value: new Uint8Array([1, 2, 3]).buffer,
 			js: 'new Uint8Array([1,2,3]).buffer',
 			json: '[["ArrayBuffer","AQID"]]'
+		},
+		{
+			name: 'Temporal.Duration',
+			value: Temporal.Duration.from({ years: 1, months: 2, days: 3 }),
+			js: 'Temporal.Duration.from("P1Y2M3D")',
+			json: '[["Temporal.Duration","P1Y2M3D"]]'
+		},
+		{
+			name: 'Temporal.Instant',
+			value: Temporal.Instant.from("1999-09-29T05:30:00Z"),
+			js: 'Temporal.Instant.from("1999-09-29T05:30:00Z")',
+			json: '[["Temporal.Instant","1999-09-29T05:30:00Z"]]'
+		},
+		{
+			name: 'Temporal.PlainDate',
+			value: Temporal.PlainDate.from({ year: 1999, month: 9, day: 29 }),
+			js: 'Temporal.PlainDate.from("1999-09-29")',
+			json: '[["Temporal.PlainDate","1999-09-29"]]'
+		},
+		{
+			name: 'Temporal.PlainTime',
+			value: Temporal.PlainTime.from({ hour: 12, minute: 34, second: 56 }),
+			js: 'Temporal.PlainTime.from("12:34:56")',
+			json: '[["Temporal.PlainTime","12:34:56"]]'
+		},
+		{
+			name: 'Temporal.PlainDateTime',
+			value: Temporal.PlainDateTime.from({
+				year: 1999, month: 9, day: 29,
+				hour: 12, minute: 34, second: 56
+			}),
+			js: 'Temporal.PlainDateTime.from("1999-09-29T12:34:56")',
+			json: '[["Temporal.PlainDateTime","1999-09-29T12:34:56"]]'
+		},
+		{
+			name: 'Temporal.PlainMonthDay',
+			value: Temporal.PlainMonthDay.from({ month: 9, day: 29 }),
+			js: 'Temporal.PlainMonthDay.from("09-29")',
+			json: '[["Temporal.PlainMonthDay","09-29"]]'
+		},
+		{
+			name: 'Temporal.PlainYearMonth',
+			value: Temporal.PlainYearMonth.from({ year: 1999, month: 9 }),
+			js: 'Temporal.PlainYearMonth.from("1999-09")',
+			json: '[["Temporal.PlainYearMonth","1999-09"]]'
+		},
+		{
+			name: 'Temporal.ZonedDateTime',
+			value: Temporal.ZonedDateTime.from({
+				year: 1999, month: 9, day: 29,
+				hour: 12, minute: 34, second: 56,
+				timeZone: 'Europe/Rome'
+			}),
+			js: 'Temporal.ZonedDateTime.from("1999-09-29T12:34:56+02:00[Europe/Rome]")',
+			json: '[["Temporal.ZonedDateTime","1999-09-29T12:34:56+02:00[Europe/Rome]"]]'
 		}
 	],