diff --git a/ncurses/base/lib_slkinit.c b/ncurses/base/lib_slkinit.c
index 9cbdfea..318077f 100644
--- a/ncurses/base/lib_slkinit.c
+++ b/ncurses/base/lib_slkinit.c
@@ -1,5 +1,6 @@
 /****************************************************************************
- * Copyright (c) 1998-2008,2009 Free Software Foundation, Inc.              *
+ * Copyright 2020,2022 Thomas E. Dickey                                     *
+ * Copyright 1998-2009,2017 Free Software Foundation, Inc.                  *
  *                                                                          *
  * Permission is hereby granted, free of charge, to any person obtaining a  *
  * copy of this software and associated documentation files (the            *
@@ -40,7 +41,7 @@
  */
 #include <curses.priv.h>
 
-MODULE_ID("$Id: lib_slkinit.c,v 1.13 2009/10/31 00:10:46 tom Exp $")
+MODULE_ID("$Id: lib_slkinit.c,v 1.16 2022/07/09 18:58:58 tom Exp $")
 
 #ifdef USE_SP_RIPOFF
 #define SoftkeyFormat SP_PARM->slk_format
@@ -75,6 +76,14 @@
 NCURSES_EXPORT(int)
 slk_init(int format)
 {
-    return NCURSES_SP_NAME(slk_init) (CURRENT_SCREEN_PRE, format);
+    int rc;
+
+    _nc_init_pthreads();
+    _nc_lock_global(prescreen);
+    START_TRACE();
+    rc = NCURSES_SP_NAME(slk_init) (CURRENT_SCREEN_PRE, format);
+    _nc_unlock_global(prescreen);
+
+    return rc;
 }
 #endif