diff --git a/src/increase/_base_client.py b/src/increase/_base_client.py
index e9896b7e7..d0b5bbeb8 100644
--- a/src/increase/_base_client.py
+++ b/src/increase/_base_client.py
@@ -771,7 +771,7 @@ def _should_retry(self, response: httpx.Response) -> bool:
         return False
 
     def _idempotency_key(self) -> str:
-        return f"stainless-python-retry-{uuid.uuid4()}"
+        return f"increase-python-retry-{uuid.uuid4()}"
 
 
 class _DefaultHttpxClient(httpx.Client):
diff --git a/tests/test_client.py b/tests/test_client.py
index b44f788b5..fcc93f9ab 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -555,7 +555,7 @@ def test_idempotency_header_options(self, respx_mock: MockRouter) -> None:
 
         header = response.request.headers.get("Idempotency-Key")
         assert header is not None
-        assert header.startswith("stainless-python-retry")
+        assert header.startswith("increase-python-retry")
 
         # explicit header
         response = self.client.post(
@@ -1409,7 +1409,7 @@ async def test_idempotency_header_options(self, respx_mock: MockRouter) -> None:
 
         header = response.request.headers.get("Idempotency-Key")
         assert header is not None
-        assert header.startswith("stainless-python-retry")
+        assert header.startswith("increase-python-retry")
 
         # explicit header
         response = await self.client.post(