diff --git a/test/net/http/test_http.rb b/test/net/http/test_http.rb
index c05c5f79c6..22448d828f 100644
--- a/test/net/http/test_http.rb
+++ b/test/net/http/test_http.rb
@@ -569,7 +569,7 @@ module TestNetHTTP_version_1_1_methods
 
       conn = Net::HTTP.new('localhost', port)
       conn.read_timeout = EnvUtil.apply_timeout_scale(0.01)
-      conn.open_timeout = EnvUtil.apply_timeout_scale(0.1)
+      conn.open_timeout = EnvUtil.apply_timeout_scale(1)
 
       th = Thread.new do
         assert_raise(Net::ReadTimeout) {