diff --git a/lib/aws_auth/authorization_header.ex b/lib/aws_auth/authorization_header.ex
index 416615c..32ea53c 100644
--- a/lib/aws_auth/authorization_header.ex
+++ b/lib/aws_auth/authorization_header.ex
@@ -14,7 +14,6 @@ defmodule AWSAuth.AuthorizationHeader do
 
     http_method = String.upcase(http_method)
     region = String.downcase(region)
-    service = String.downcase(service)
 
     headers = Map.put_new(headers, "host", uri.host)
 
diff --git a/lib/aws_auth/query_parameters.ex b/lib/aws_auth/query_parameters.ex
index eaac984..c44bf0b 100644
--- a/lib/aws_auth/query_parameters.ex
+++ b/lib/aws_auth/query_parameters.ex
@@ -7,7 +7,6 @@ defmodule AWSAuth.QueryParameters do
 
     http_method = String.upcase(http_method)
     region = String.downcase(region)
-    service = String.downcase(service)
 
     headers = Map.put_new(headers, "host", uri.host)