diff --git a/litellm/llms/cohere/common_utils.py b/litellm/llms/cohere/common_utils.py
index 6dbe52d575..d194d9556b 100644
--- a/litellm/llms/cohere/common_utils.py
+++ b/litellm/llms/cohere/common_utils.py
@@ -31,7 +31,7 @@ def validate_environment(
         "Request-Source": "unspecified:litellm",
         "accept": "application/json",
         "content-type": "application/json",
-        "Authorization": "bearer $CO_API_KEY"
+        "Authorization": "Bearer $CO_API_KEY"
     }
     """
     headers.update(
@@ -42,7 +42,7 @@ def validate_environment(
         }
     )
     if api_key:
-        headers["Authorization"] = f"bearer {api_key}"
+        headers["Authorization"] = f"Bearer {api_key}"
     return headers
 
 
diff --git a/litellm/llms/cohere/rerank/transformation.py b/litellm/llms/cohere/rerank/transformation.py
index 6586a83f06..f9c979712d 100644
--- a/litellm/llms/cohere/rerank/transformation.py
+++ b/litellm/llms/cohere/rerank/transformation.py
@@ -86,7 +86,7 @@ class CohereRerankConfig(BaseRerankConfig):
             )
 
         default_headers = {
-            "Authorization": f"bearer {api_key}",
+            "Authorization": f"Bearer {api_key}",
             "accept": "application/json",
             "content-type": "application/json",
         }
diff --git a/litellm/llms/infinity/rerank/transformation.py b/litellm/llms/infinity/rerank/transformation.py
index 6259d445ae..55aac6033d 100644
--- a/litellm/llms/infinity/rerank/transformation.py
+++ b/litellm/llms/infinity/rerank/transformation.py
@@ -49,7 +49,7 @@ class InfinityRerankConfig(CohereRerankConfig):
             )
 
         default_headers = {
-            "Authorization": f"bearer {api_key}",
+            "Authorization": f"Bearer {api_key}",
             "accept": "application/json",
             "content-type": "application/json",
         }
diff --git a/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py b/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
index 7a0343e2e9..005b474424 100644
--- a/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
+++ b/litellm/proxy/pass_through_endpoints/pass_through_endpoints.py
@@ -84,7 +84,7 @@ async def set_env_variables_in_header(custom_headers: Optional[dict]) -> Optiona
 
     example header can be
 
-    {"Authorization": "bearer os.environ/COHERE_API_KEY"}
+    {"Authorization": "Bearer os.environ/COHERE_API_KEY"}
     """
     if custom_headers is None:
         return None
diff --git a/tests/local_testing/test_pass_through_endpoints.py b/tests/local_testing/test_pass_through_endpoints.py
index 9c5f599521..29cf9682a7 100644
--- a/tests/local_testing/test_pass_through_endpoints.py
+++ b/tests/local_testing/test_pass_through_endpoints.py
@@ -117,7 +117,7 @@ async def test_pass_through_endpoint_rerank(client):
         {
             "path": "/v1/rerank",
             "target": "https://api.cohere.com/v1/rerank",
-            "headers": {"Authorization": f"bearer {_cohere_api_key}"},
+            "headers": {"Authorization": f"Bearer {_cohere_api_key}"},
         }
     ]
 
@@ -193,7 +193,7 @@ async def test_pass_through_endpoint_rpm_limit(
             "path": "/v1/rerank",
             "target": "https://api.cohere.com/v1/rerank",
             "auth": auth,
-            "headers": {"Authorization": f"bearer {_cohere_api_key}"},
+            "headers": {"Authorization": f"Bearer {_cohere_api_key}"},
         }
     ]
 
@@ -293,7 +293,7 @@ async def test_pass_through_endpoint_sequential_rpm_limit(
             "path": "/v1/rerank",
             "target": "https://api.cohere.com/v1/rerank",
             "auth": auth,
-            "headers": {"Authorization": f"bearer {_cohere_api_key}"},
+            "headers": {"Authorization": f"Bearer {_cohere_api_key}"},
         }
     ]
 
diff --git a/tests/test_passthrough_endpoints.py b/tests/test_passthrough_endpoints.py
index a66c94c583..47ac7511aa 100644
--- a/tests/test_passthrough_endpoints.py
+++ b/tests/test_passthrough_endpoints.py
@@ -17,7 +17,7 @@ dotenv.load_dotenv()
 async def cohere_rerank(session):
     url = "http://localhost:4000/v1/rerank"
     headers = {
-        "Authorization": f"bearer {os.getenv('COHERE_API_KEY')}",
+        "Authorization": f"Bearer {os.getenv('COHERE_API_KEY')}",
         "Content-Type": "application/json",
         "Accept": "application/json",
     }