diff --git a/lib/remote_storage/riak.rb b/lib/remote_storage/riak.rb
index 14d485c..e5c129d 100644
--- a/lib/remote_storage/riak.rb
+++ b/lib/remote_storage/riak.rb
@@ -43,6 +43,7 @@ module RemoteStorage
       server.headers["Content-Type"] = object.content_type
       server.headers["Last-Modified"] = last_modified_date_for(object)
       server.headers["ETag"] = object.etag
+      server.headers["Content-Length"] = object_size(object)
 
       server.halt 304 if server.env["HTTP_IF_NONE_MATCH"] == object.etag
 
diff --git a/spec/riak_spec.rb b/spec/riak_spec.rb
index ac23f14..406ffc1 100644
--- a/spec/riak_spec.rb
+++ b/spec/riak_spec.rb
@@ -38,6 +38,11 @@ describe "App with Riak backend" do
       last_response.headers["ETag"].wont_be_nil
     end
 
+    it "has a Content-Length header set" do
+      last_response.status.must_equal 200
+      last_response.headers["Content-Length"].must_equal "14"
+    end
+
     it "has caching headers set" do
       last_response.status.must_equal 200
       last_response.headers["Expires"].must_equal "0"
@@ -385,6 +390,12 @@ describe "App with Riak backend" do
             last_response.headers["ETag"].must_equal etag
           end
 
+          it "responds with a Content-Length header" do
+            get "/jimmy/documents/jaypeg"
+
+            last_response.headers["Content-Length"].must_equal "16044"
+          end
+
           it "changes the ETag when updating the file" do
             old_etag = last_response.headers["ETag"]
             put "/jimmy/documents/jaypeg", @image