diff --git a/source/index.ts b/source/index.ts
index aab38cc..8ee546f 100644
--- a/source/index.ts
+++ b/source/index.ts
@@ -361,7 +361,7 @@ is.emptyMap = (value: unknown): value is Map<never, never> => is.map(value) && v
 is.nonEmptyMap = <Key = unknown, Value = unknown>(value: unknown): value is Map<Key, Value> => is.map(value) && value.size > 0;
 
 /**
-Returns `true` if `value` can be used as an object property key (either a `string`, a `number` or a `symbol`).
+`PropertyKey` is any value that can be used as an object key (string, number, or symbol)
 */
 is.propertyKey = (value: unknown): value is PropertyKey => is.any([is.string, is.number, is.symbol], value);