diff --git a/src/ruby/qps/worker.rb b/src/ruby/qps/worker.rb
index 8555888106ddf2212410dece8c837cc4280a4802..208211c4108e4f38698169332a3c2c2c07e14b69 100755
--- a/src/ruby/qps/worker.rb
+++ b/src/ruby/qps/worker.rb
@@ -71,6 +71,7 @@ class WorkerServiceImpl < Grpc::Testing::WorkerService::Service
   def run_client(reqs)
     q = EnumeratorQueue.new(self)
     Thread.new {
+      client = ''
       reqs.each do |req|
         case req.argtype
         when 'setup'