diff --git a/.changeset/smooth-actors-tickle.md b/.changeset/smooth-actors-tickle.md
new file mode 100644
index 000000000..6eb7b748d
--- /dev/null
+++ b/.changeset/smooth-actors-tickle.md
@@ -0,0 +1,5 @@
+---
+"openapi-fetch": patch
+---
+
+Fix typing for environments without DOM lib
diff --git a/packages/openapi-fetch/src/index.d.ts b/packages/openapi-fetch/src/index.d.ts
index 2ba91147f..e7e7f96b6 100644
--- a/packages/openapi-fetch/src/index.d.ts
+++ b/packages/openapi-fetch/src/index.d.ts
@@ -24,7 +24,7 @@ export interface ClientOptions extends Omit<RequestInit, "headers"> {
 }
 
 export type HeadersOptions =
-  | HeadersInit
+  | Required<RequestInit>["headers"]
   | Record<string, string | number | boolean | (string | number | boolean)[] | null | undefined>;
 
 export type QuerySerializer<T> = (