diff --git a/lib/rb/spec/server_spec.rb b/lib/rb/spec/server_spec.rb
index ee58c7c..57f5237 100644
--- a/lib/rb/spec/server_spec.rb
+++ b/lib/rb/spec/server_spec.rb
@@ -144,6 +144,7 @@
         exception_q.push(StandardError.new('ERROR'))
       end
       expect { @server.rescuable_serve }.to(raise_error('ERROR'))
+      sleep(0.15)
     end
 
     it "should avoid running the server twice when retrying rescuable_serve" do
diff --git a/lib/rb/thrift.gemspec b/lib/rb/thrift.gemspec
index fcc344f..0f96c3f 100644
--- a/lib/rb/thrift.gemspec
+++ b/lib/rb/thrift.gemspec
@@ -34,7 +34,7 @@
   s.add_development_dependency 'rack',               '~> 2.0'
   s.add_development_dependency 'rack-test',          '~> 0.8.3'
   s.add_development_dependency 'rake',               '~> 12.3'
-  s.add_development_dependency 'rspec',              '~> 3.5'
+  s.add_development_dependency 'rspec',              '~> 3.7'
   s.add_development_dependency 'thin',               '~> 1.7'
 end