diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index cbff9d4a..ccb3566a 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.90.2"
+  ".": "0.90.3"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index c5254b76..40143a4b 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 156
 openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/lithic%2Flithic-18973e063e9e9233433290bb4d641df8e17e1f21f5b1ec57e00182f0a48dbdec.yml
 openapi_spec_hash: ab503dc3772f962b603ade7b91b8534c
-config_hash: 6729d695e399d14fff4891b6b82ec86c
+config_hash: cb39eda3ababfc0a6d3a5ac0c2a5ec7a
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4d99a9a7..7067ee44 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,14 @@
 # Changelog
 
+## 0.90.3 (2025-04-14)
+
+Full Changelog: [v0.90.2...v0.90.3](https://github.com/lithic-com/lithic-python/compare/v0.90.2...v0.90.3)
+
+### Chores
+
+* **client:** minor internal fixes ([67e2aa9](https://github.com/lithic-com/lithic-python/commit/67e2aa9108a631f0c97fea32cd8e4519944f0ffd))
+* **internal:** update pyright settings ([04ac3ad](https://github.com/lithic-com/lithic-python/commit/04ac3adac96fd5c2fc7d6eb0db21e396f0764d63))
+
 ## 0.90.2 (2025-04-11)
 
 Full Changelog: [v0.90.1...v0.90.2](https://github.com/lithic-com/lithic-python/compare/v0.90.1...v0.90.2)
diff --git a/mypy.ini b/mypy.ini
index c0bb47f6..d895d267 100644
--- a/mypy.ini
+++ b/mypy.ini
@@ -8,7 +8,7 @@ show_error_codes = True
 #
 # We also exclude our `tests` as mypy doesn't always infer
 # types correctly and Pyright will still catch any type errors.
-exclude = ^(src/lithic/_files\.py|_dev/.*\.py|tests/.*|src/lithic/resources/external_bank_accounts/external_bank_accounts\.py)$
+exclude = ^(src/lithic/_files\.py|_dev/.*\.py|tests/.*)$
 
 strict_equality = True
 implicit_reexport = True
diff --git a/pyproject.toml b/pyproject.toml
index 503b9057..a97db1ee 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "lithic"
-version = "0.90.2"
+version = "0.90.3"
 description = "The official Python library for the lithic API"
 dynamic = ["readme"]
 license = "Apache-2.0"
@@ -147,11 +147,10 @@ exclude = [
 ]
 
 reportImplicitOverride = true
+reportOverlappingOverload = false
 
 reportImportCycles = false
 reportPrivateUsage = false
-reportOverlappingOverload = false
-
 
 [tool.ruff]
 line-length = 120
diff --git a/src/lithic/_base_client.py b/src/lithic/_base_client.py
index c3a3eb97..108ac3fc 100644
--- a/src/lithic/_base_client.py
+++ b/src/lithic/_base_client.py
@@ -410,7 +410,8 @@ def _build_headers(self, options: FinalRequestOptions, *, retries_taken: int = 0
 
         idempotency_header = self._idempotency_header
         if idempotency_header and options.method.lower() != "get" and idempotency_header not in headers:
-            headers[idempotency_header] = options.idempotency_key or self._idempotency_key()
+            options.idempotency_key = options.idempotency_key or self._idempotency_key()
+            headers[idempotency_header] = options.idempotency_key
 
         # Don't set these headers if they were already set or removed by the caller. We check
         # `custom_headers`, which can contain `Omit()`, instead of `headers` to account for the removal case.
@@ -944,6 +945,10 @@ def _request(
         request = self._build_request(options, retries_taken=retries_taken)
         self._prepare_request(request)
 
+        if options.idempotency_key:
+            # ensure the idempotency key is reused between requests
+            input_options.idempotency_key = options.idempotency_key
+
         kwargs: HttpxSendArgs = {}
         if self.custom_auth is not None:
             kwargs["auth"] = self.custom_auth
@@ -1490,6 +1495,10 @@ async def _request(
         request = self._build_request(options, retries_taken=retries_taken)
         await self._prepare_request(request)
 
+        if options.idempotency_key:
+            # ensure the idempotency key is reused between requests
+            input_options.idempotency_key = options.idempotency_key
+
         kwargs: HttpxSendArgs = {}
         if self.custom_auth is not None:
             kwargs["auth"] = self.custom_auth
diff --git a/src/lithic/_version.py b/src/lithic/_version.py
index 5cb01030..92b76556 100644
--- a/src/lithic/_version.py
+++ b/src/lithic/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "lithic"
-__version__ = "0.90.2"  # x-release-please-version
+__version__ = "0.90.3"  # x-release-please-version