diff --git a/lib/azure/core/http/http_request.rb b/lib/azure/core/http/http_request.rb
index 5fdd38e..9bf9dde 100755
--- a/lib/azure/core/http/http_request.rb
+++ b/lib/azure/core/http/http_request.rb
@@ -185,8 +185,8 @@ def apply_string_io_headers
         end
 
         def apply_miscellaneous_headers
-          headers['Content-Length'] = body.bytesize.to_s
-          headers['Content-MD5'] = Base64.strict_encode64(Digest::MD5.digest(body)) unless headers['Content-MD5']
+          headers['Content-Length'] = body.size.to_s
+          headers['Content-MD5'] = Base64.strict_encode64(Digest::MD5.digest(body.to_s)) unless headers['Content-MD5']
         end
       end
     end