diff --git a/t/20-sign.t b/t/20-sign.t
index dcc008c..f5ef6ac 100644
--- a/t/20-sign.t
+++ b/t/20-sign.t
@@ -1,6 +1,6 @@
 #!perl
 
-use Test::More tests => 6;
+use Test::More tests => 7;
 
 BEGIN {
     use_ok( 'Net::Amazon::Signature::V4' ) || print "Bail out!\n";
@@ -9,6 +9,7 @@ BEGIN {
 use Net::Amazon::Signature::V4;
 use HTTP::Request;
 
+my $sha = '0123456789abcfdef0123456789abcfdef0123456789abcfdef0123456789abcfdef';
 my $sig = Net::Amazon::Signature::V4->new(
     'AKIDEXAMPLE',
     'wJalrXUtnFEMI/K7MDENG+bPxRfiCYEXAMPLEKEY',
@@ -24,3 +25,7 @@ isnt($signed_req->header("x-amz-date"), '', "Inserted x-amz-date header");
 isnt($signed_req->header("authorization"), '', "Inserted authorization header");
 isnt($signed_req->header("X-Amz-Content-Sha256"), '', "Inserted x-amz-content-sha256 header");
 
+my $req = HTTP::Request->new( 'GET', 'http://hostname.example.net/something/cool' );
+$req->header("X-Amz-Content-Sha256",$sha);
+my $signed_req = $sig->sign( $req );
+is($signed_req->header("X-Amz-Content-Sha256"), $sha, "x-amz-content-sha256 is kept");