diff --git a/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/account_id.rb b/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/account_id.rb
index 00f1e3aac8c..d9654a86a8f 100644
--- a/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/account_id.rb
+++ b/gems/aws-sdk-glacier/lib/aws-sdk-glacier/plugins/account_id.rb
@@ -16,8 +16,10 @@ class AccountId < Seahorse::Client::Plugin
 
         class Handler < Seahorse::Client::Handler
           def call(context)
-            context.params[:account_id] = nil if context.params[:account_id].empty?
             context.params[:account_id] ||= context.config.account_id
+            if context.params[:account_id].empty?
+              context.params[:account_id] = '-'
+            end
             @handler.call(context)
           end
         end
diff --git a/gems/aws-sdk-s3/spec/client_spec.rb b/gems/aws-sdk-s3/spec/client_spec.rb
index ca3534d8e21..bbd262193d0 100644
--- a/gems/aws-sdk-s3/spec/client_spec.rb
+++ b/gems/aws-sdk-s3/spec/client_spec.rb
@@ -492,7 +492,7 @@ module S3
         it 'uses path style addressing for DNS incompatible bucket names' do
           client = Client.new(stub_responses: true)
           resp = client.head_bucket(bucket: 'Bucket123')
-          expect(resp.context.http_request.endpoint.path).to eq('/Bucket123/')
+          expect(resp.context.http_request.endpoint.path).to eq('/Bucket123')
         end
       end