diff --git a/include/ruby/internal/intern/process.h b/include/ruby/internal/intern/process.h
index 7a7b24ed4b..5dcf85e80c 100644
--- a/include/ruby/internal/intern/process.h
+++ b/include/ruby/internal/intern/process.h
@@ -30,6 +30,15 @@ RBIMPL_SYMBOL_EXPORT_BEGIN()
 
 /* process.c */
 
+/**
+ * Wait for the specified process to terminate, reap it, and return its status.
+ *
+ * @param[in] pid The process ID to wait for.
+ * @param[in] flags The flags to pass to waitpid(2).
+ * @return VALUE An instance of Process::Status.
+ */
+VALUE rb_process_status_wait(rb_pid_t pid, int flags);
+
 /**
  * Sets the "last status", or the `$?`.
  *
diff --git a/process.c b/process.c
index 5468cf0846..377da3829a 100644
--- a/process.c
+++ b/process.c
@@ -1197,7 +1197,7 @@ rb_process_status_wait(rb_pid_t pid, int flags)
  *  This is an EXPERIMENTAL FEATURE.
  */
 
-VALUE
+static VALUE
 rb_process_status_waitv(int argc, VALUE *argv, VALUE _)
 {
     rb_check_arity(argc, 0, 2);