1 files changed, 5 insertions, 0 deletions
diff --git a/process.c b/process.c
index acb5b66156..88b55ed335 100644
--- a/process.c
+++ b/process.c
@@ -4227,12 +4227,17 @@ rb_fork_ruby(int *status)
         prefork();
 
         before_fork_ruby();
+        rb_thread_acquire_fork_lock();
         disable_child_handler_before_fork(&old);
 
         child.pid = pid = rb_fork();
         child.error = err = errno;
 
         disable_child_handler_fork_parent(&old); /* yes, bad name */
+        rb_thread_release_fork_lock();
+        if (pid == 0) {
+          rb_thread_reset_fork_lock();
+        }
         after_fork_ruby(pid);
 
         /* repeat while fork failed but retryable */