From 93d78107bb6889bc26dd4ec44b4f5c454af3e281 Mon Sep 17 00:00:00 2001
From: Phil Pluckthun <phil@kitten.sh>
Date: Sun, 1 Feb 2026 22:48:54 +0000
Subject: [PATCH] fix: Add `Content-Length: 0` for empty `PATCH` bodies (#23)

---
 .changeset/every-coats-decide.md | 5 +++++
 src/fetch.ts                     | 5 ++++-
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/every-coats-decide.md

diff --git a/.changeset/every-coats-decide.md b/.changeset/every-coats-decide.md
new file mode 100644
index 0000000..7c4ffb5
--- /dev/null
+++ b/.changeset/every-coats-decide.md
@@ -0,0 +1,5 @@
+---
+'fetch-nodeshim': patch
+---
+
+Set `Content-Length: 0` when `response.body` is `null` for `PATCH` as well
diff --git a/src/fetch.ts b/src/fetch.ts
index 601e46b..2825bbd 100644
--- a/src/fetch.ts
+++ b/src/fetch.ts
@@ -253,7 +253,10 @@ async function _fetch(
     if (requestBody.contentType)
       requestHeaders.set('Content-Type', requestBody.contentType);
 
-    if (requestBody.body == null && (method === 'POST' || method === 'PUT')) {
+    if (
+      requestBody.body == null &&
+      (method === 'POST' || method === 'PUT' || method === 'PATCH')
+    ) {
       requestHeaders.set('Content-Length', '0');
     } else if (requestBody.body != null && requestBody.contentLength != null) {
       requestHeaders.set('Content-Length', `${requestBody.contentLength}`);
-- 
2.51.2