diff --git a/src/index.ts b/src/index.ts
index b1e4bb2..2e536dd 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -460,7 +460,7 @@ export const temporalToString = (
   value: TemporalValue,
   timezone?: Timezone
 ): string => {
-  if ('epochMilliseconds' in value)
+  if (typeof value.epochMilliseconds === 'number')
     return dateToString(new Date(value.epochMilliseconds), timezone || 'local');
 
   if (value[Symbol.toStringTag] === 'Temporal.PlainDateTime')
diff --git a/src/types.ts b/src/types.ts
index 45593a9..f857ce1 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -2,15 +2,12 @@ export type Raw = {
   toSqlString(): string;
 };
 
-export type TemporalValue =
-  | Temporal.Instant
-  | Temporal.ZonedDateTime
-  | Temporal.PlainDateTime
-  | Temporal.PlainDate
-  | Temporal.PlainTime
-  | Temporal.PlainYearMonth
-  | Temporal.PlainMonthDay
-  | Temporal.Duration;
+/** Avoids the global `Temporal` namespace so consumers don't need TS's ESNext.Temporal lib. */
+export type TemporalValue = {
+  readonly [Symbol.toStringTag]: `Temporal.${string}`;
+  readonly epochMilliseconds?: number;
+  toString(): string;
+};
 
 export type SqlValue =
   | string
diff --git a/tsconfig.json b/tsconfig.json
index 66b7bd6..35d8f04 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -2,7 +2,7 @@
   "include": ["src"],
   "compilerOptions": {
     "target": "ES2018",
-    "lib": ["ES2018", "ESNext.Temporal"],
+    "lib": ["ES2018"],
     "module": "Node16",
     "moduleResolution": "Node16",
     "rootDir": "src",