diff --git a/.changeset/unlucky-berries-boil.md b/.changeset/unlucky-berries-boil.md
new file mode 100644
index 000000000..f5fc2674f
--- /dev/null
+++ b/.changeset/unlucky-berries-boil.md
@@ -0,0 +1,5 @@
+---
+"@fp-ts/core": patch
+---
+
+Option: change `firstSomeOf` signature
diff --git a/Option.md b/Option.md
index f14db0ff5..339a09093 100644
--- a/Option.md
+++ b/Option.md
@@ -333,6 +333,6 @@ console.log(output); // Output: Error: Cannot parse 'Not a number' as a number
| `getOrUndefined` | `Option` | `A \| undefined` |
| `orElse` | `Option`, `Option` | `Option` |
| `orElseEither` | `Option`, `Option` | `Option>` |
-| `firstSomeOf` | `Option`, `Iterable