diff --git a/src/anthropic/lib/aws/_client.py b/src/anthropic/lib/aws/_client.py
index 31d577124..009a195fe 100644
--- a/src/anthropic/lib/aws/_client.py
+++ b/src/anthropic/lib/aws/_client.py
@@ -136,6 +136,16 @@ def _api_key_auth(self) -> dict[str, str]:
             return {}
         return super()._api_key_auth
 
+    @property
+    @override
+    def _bearer_auth(self) -> dict[str, str]:
+        # skip_auth must also silence ambient bearer credentials: the parent
+        # constructor falls back to ANTHROPIC_AUTH_TOKEN from the environment,
+        # and a leaked Authorization header defeats the point of skip_auth.
+        if self._skip_auth:
+            return {}
+        return super()._bearer_auth
+
     @override
     def _validate_headers(self, headers: httpx.Headers, omitted: frozenset[str]) -> None:
         if self._use_sigv4 or self._skip_auth:
@@ -344,6 +354,16 @@ def _api_key_auth(self) -> dict[str, str]:
             return {}
         return super()._api_key_auth
 
+    @property
+    @override
+    def _bearer_auth(self) -> dict[str, str]:
+        # skip_auth must also silence ambient bearer credentials: the parent
+        # constructor falls back to ANTHROPIC_AUTH_TOKEN from the environment,
+        # and a leaked Authorization header defeats the point of skip_auth.
+        if self._skip_auth:
+            return {}
+        return super()._bearer_auth
+
     @override
     def _validate_headers(self, headers: httpx.Headers, omitted: frozenset[str]) -> None:
         if self._use_sigv4 or self._skip_auth: