diff --git a/lib/aws_auth/authorization_header.ex b/lib/aws_auth/authorization_header.ex
index 416615c..b108a69 100644
--- a/lib/aws_auth/authorization_header.ex
+++ b/lib/aws_auth/authorization_header.ex
@@ -18,7 +18,11 @@ defmodule AWSAuth.AuthorizationHeader do
 
     headers = Map.put_new(headers, "host", uri.host)
 
-    payload = AWSAuth.Utils.hash_sha256(payload)
+    payload = if payload == :hashed do
+      payload
+    else
+      AWSAuth.Utils.hash_sha256(payload)
+    end
 
     headers = Map.put_new(headers, "x-amz-content-sha256", payload)
 
diff --git a/lib/aws_auth/utils.ex b/lib/aws_auth/utils.ex
index bd188ce..e2387cb 100644
--- a/lib/aws_auth/utils.ex
+++ b/lib/aws_auth/utils.ex
@@ -13,9 +13,11 @@ defmodule AWSAuth.Utils do
     |> Enum.sort(&(&1 < &2))
     |> Enum.join(";")
 
-    hashed_payload = if hashed_payload == :unsigned,
-      do: "UNSIGNED-PAYLOAD",
-      else: hashed_payload
+    hashed_payload = case hashed_payload do
+      :unsigned -> "UNSIGNED-PAYLOAD"
+      :hashed -> headers["x-amz-content-sha256"]
+      _ -> hashed_payload
+    end
 
     encoded_path =
       path