diff --git a/util/threadpool_imp.cc b/util/threadpool_imp.cc
index f38e6422b..10b5d4361 100644
--- a/util/threadpool_imp.cc
+++ b/util/threadpool_imp.cc
@@ -147,6 +147,9 @@ void ThreadPoolImpl::Impl::JoinThreads(bool wait_for_jobs_to_complete) {
 
   wait_for_jobs_to_complete_ = wait_for_jobs_to_complete;
   exit_all_threads_ = true;
+  // prevent threads from being recreated right after they're joined, in case
+  // the user is concurrently submitting jobs.
+  total_threads_limit_ = 0;
 
   lock.unlock();