diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index da59f99..3e2bf49 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.4.0"
+  ".": "0.4.1"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index bc3166c..dcb3502 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 32
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/dedalus-labs/dedalus-a63ad804ae8ee532d57afae307595dae02d2a6924f83657430b3579193560775.yml
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/dedalus-labs/dedalus-32ccb3c17674e0ee68fd6eafbdd0f210bccfd09fce0702e28b8278e06678deec.yml
 openapi_spec_hash: ccb02923079d91569a17162c88da590b
-config_hash: 0e31b0b75cafdbc25febc2b7ca219799
+config_hash: 3b16603a18779d453842a0d56638384d
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f7ec47b..e2f30ac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 0.4.1 (2026-06-17)
+
+Full Changelog: [v0.4.0...v0.4.1](https://github.com/dedalus-labs/dedalus-python/compare/v0.4.0...v0.4.1)
+
+### Bug Fixes
+
+* **auth:** prioritize first auth header ([81f3c28](https://github.com/dedalus-labs/dedalus-python/commit/81f3c288b2ae2e97046344177500714e1e4ce6be))
+
 ## 0.4.0 (2026-05-12)
 
 Full Changelog: [v0.3.0...v0.4.0](https://github.com/dedalus-labs/dedalus-python/compare/v0.3.0...v0.4.0)
diff --git a/pyproject.toml b/pyproject.toml
index 9fa189c..678b72c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "dedalus-sdk"
-version = "0.4.0"
+version = "0.4.1"
 description = "The official Python library for the Dedalus API"
 dynamic = ["readme"]
 license = "MIT"
diff --git a/src/dedalus_sdk/_client.py b/src/dedalus_sdk/_client.py
index c6dc994..ec68f90 100644
--- a/src/dedalus_sdk/_client.py
+++ b/src/dedalus_sdk/_client.py
@@ -161,10 +161,14 @@ def qs(self) -> Querystring:
 
     @override
     def _auth_headers(self, security: SecurityOptions) -> dict[str, str]:
-        return {
-            **(self._api_key_auth if security.get("api_key_auth", False) else {}),
-            **(self._bearer_auth if security.get("bearer_auth", False) else {}),
-        }
+        headers: dict[str, str] = {}
+        if security.get("api_key_auth", False):
+            for key, value in self._api_key_auth.items():
+                headers.setdefault(key, value)
+        if security.get("bearer_auth", False):
+            for key, value in self._bearer_auth.items():
+                headers.setdefault(key, value)
+        return headers
 
     @property
     def _api_key_auth(self) -> dict[str, str]:
@@ -410,10 +414,14 @@ def qs(self) -> Querystring:
 
     @override
     def _auth_headers(self, security: SecurityOptions) -> dict[str, str]:
-        return {
-            **(self._api_key_auth if security.get("api_key_auth", False) else {}),
-            **(self._bearer_auth if security.get("bearer_auth", False) else {}),
-        }
+        headers: dict[str, str] = {}
+        if security.get("api_key_auth", False):
+            for key, value in self._api_key_auth.items():
+                headers.setdefault(key, value)
+        if security.get("bearer_auth", False):
+            for key, value in self._bearer_auth.items():
+                headers.setdefault(key, value)
+        return headers
 
     @property
     def _api_key_auth(self) -> dict[str, str]:
diff --git a/src/dedalus_sdk/_version.py b/src/dedalus_sdk/_version.py
index ff44f48..6618e17 100644
--- a/src/dedalus_sdk/_version.py
+++ b/src/dedalus_sdk/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "dedalus_sdk"
-__version__ = "0.4.0"  # x-release-please-version
+__version__ = "0.4.1"  # x-release-please-version