Index: lib/alexandria/book_providers/amazon_ecs_util.rb
===================================================================
--- lib/alexandria/book_providers/amazon_ecs_util.rb	(revision 1133)
+++ lib/alexandria/book_providers/amazon_ecs_util.rb	(working copy)
@@ -33,7 +33,6 @@
 require 'cgi'
 
 require 'digest/sha2'
-require 'base64'
 
 
 module Amazon
@@ -292,7 +291,7 @@
 
       # Step 8 : Calculate RFC 2104-compliant HMAC with SHA256 hash algorithm
       sig = hmac_sha256(string_to_sign, @@secret_access_key)     
-      base64_sig = Base64.encode64(sig).strip
+      base64_sig = [sig].pack('m').strip
       
       # Step 9 : URL-encode + and = in sig
       base64_sig = CGI.escape(base64_sig)