diff --git a/base/client.jl b/base/client.jl
index 2527d382c695d..a6d02b798c04b 100644
--- a/base/client.jl
+++ b/base/client.jl
@@ -552,6 +552,7 @@ function _start()
     append!(ARGS, Core.ARGS)
     # clear any postoutput hooks that were saved in the sysimage
     empty!(Base.postoutput_hooks)
+    Base.Experimental.make_io_thread()
     local ret = 0
     try
         repl_was_requested = exec_options(JLOptions())