diff -up ypserv-2.29/lib/yp_db.c.dbopen ypserv-2.29/lib/yp_db.c
--- ypserv-2.29/lib/yp_db.c.dbopen	2012-05-30 13:28:49.000000000 +0200
+++ ypserv-2.29/lib/yp_db.c	2013-01-28 12:07:28.555350199 +0100
@@ -173,11 +173,14 @@ _db_open (const char *domain, const char
       sprintf (buf, "%s/%s", domain, map);
 
       dbp = tcbdbnew ();
-      isok = tcbdbopen (dbp, buf, BDBOREADER);
+      isok = tcbdbopen (dbp, buf, BDBOREADER | BDBONOLCK);
 
       if (debug_flag && !isok)
-      	log_msg ("tcbdbopen: Tokyo Cabinet Error: %s", 
-                 tcbdberrmsg (tcbdbecode (dbp)));
+        {
+      	  log_msg ("tcbdbopen: Tokyo Cabinet Error: %s", 
+                   tcbdberrmsg (tcbdbecode (dbp)));
+      	  log_msg ("tcbdbopen: consider rebuilding maps using ypinit");
+      	}
       else if (debug_flag)
 	log_msg ("\t\t->Returning OK!");
     }
diff -up ypserv-2.29/makedbm/makedbm.c.dbopen ypserv-2.29/makedbm/makedbm.c
--- ypserv-2.29/makedbm/makedbm.c.dbopen	2012-05-30 13:28:49.000000000 +0200
+++ ypserv-2.29/makedbm/makedbm.c	2013-01-28 12:23:50.243283071 +0100
@@ -490,6 +490,9 @@ create_file (char *fileName, char *dbmNa
 #endif
 #else
   unlink (dbmName);
+#if defined(HAVE_LIBTC)
+	  chmod(filename, S_IRUSR|S_IWUSR);
+#endif
   rename (filename, dbmName);
 #endif
   free (filename);
@@ -508,7 +511,7 @@ dump_file (char *dbmName)
   dbm = dbm_open (dbmName, O_RDONLY, 0600);
 #elif defined(HAVE_LIBTC)
   dbm = tcbdbnew();
-  if (!tcbdbopen (dbm, dbmName, BDBOREADER))
+  if (!tcbdbopen (dbm, dbmName, BDBOREADER | BDBONOLCK))
   {
     tcbdbdel(dbm);
     dbm = NULL;
@@ -517,6 +520,7 @@ dump_file (char *dbmName)
   if (dbm == NULL)
     {
       fprintf (stderr, "makedbm: Cannot open %s\n", dbmName);
+      fprintf (stderr, "makedbm: Consider rebuilding maps using ypinit\n");
       exit (1);
     }
 #if defined(HAVE_COMPAT_LIBGDBM)
diff -up ypserv-2.29/yphelper/yphelper.c.dbopen ypserv-2.29/yphelper/yphelper.c
--- ypserv-2.29/yphelper/yphelper.c.dbopen	2012-05-30 13:28:50.000000000 +0200
+++ ypserv-2.29/yphelper/yphelper.c	2013-01-28 12:24:14.378281420 +0100
@@ -507,10 +507,10 @@ get_dbm_entry (char *key, char *map, cha
 #if defined(HAVE_COMPAT_LIBGDBM)
   dbm = gdbm_open (mappath, 0, GDBM_READER, 0600, NULL);
 #elif defined(HAVE_NDBM)
-  dbm = dbm_open (mappath, O_CREAT | O_RDWR, 0600);
+  dbm = dbm_open (mappath, O_RDONLY, 0600);
 #elif defined(HAVE_LIBTC)
   dbm = tcbdbnew();
-  if (!tcbdbopen(dbm, mappath, BDBOWRITER | BDBOCREAT))
+  if (!tcbdbopen(dbm, mappath, BDBOREADER | BDBONOLCK))
     {
       tcbdbdel(dbm);
       dbm = NULL;
@@ -519,6 +519,7 @@ get_dbm_entry (char *key, char *map, cha
   if (dbm == NULL)
     {
       fprintf (stderr, "yphelper: cannot open %s\n", mappath);
+      fprintf (stderr, "yphelper: consider rebuilding maps using ypinit\n", mappath);
       exit (1);
     }
 
diff -up ypserv-2.29/yppush/yppush.c.dbopen ypserv-2.29/yppush/yppush.c
--- ypserv-2.29/yppush/yppush.c.dbopen	2012-08-30 09:53:16.000000000 +0200
+++ ypserv-2.29/yppush/yppush.c	2013-01-28 12:23:59.161282461 +0100
@@ -290,10 +290,10 @@ get_dbm_entry (char *key)
 #if defined(HAVE_COMPAT_LIBGDBM)
   dbm = gdbm_open (mappath, 0, GDBM_READER, 0600, NULL);
 #elif defined(HAVE_NDBM)
-  dbm = dbm_open (mappath, O_CREAT | O_RDWR, 0600);
+  dbm = dbm_open (mappath, O_RDONLY, 0600);
 #elif defined(HAVE_LIBTC)
   dbm = tcbdbnew();
-  if (!tcbdbopen(dbm, mappath, BDBOWRITER | BDBOCREAT))
+  if (!tcbdbopen(dbm, mappath, BDBOREADER | BDBONOLCK))
     {
       tcbdbdel(dbm);
       dbm = NULL;
@@ -302,6 +302,7 @@ get_dbm_entry (char *key)
   if (dbm == NULL)
     {
       log_msg ("YPPUSH: Cannot open %s", mappath);
+      log_msg ("YPPUSH: consider rebuilding maps using ypinit");
       exit (1);
     }
 
diff -up ypserv-2.29/ypxfr/ypxfr.c.dbopen ypserv-2.29/ypxfr/ypxfr.c
--- ypserv-2.29/ypxfr/ypxfr.c.dbopen	2013-01-28 12:07:28.475350204 +0100
+++ ypserv-2.29/ypxfr/ypxfr.c	2013-01-28 12:24:07.195281912 +0100
@@ -557,10 +557,10 @@ ypxfr (char *map, char *source_host, cha
 #if defined(HAVE_COMPAT_LIBGDBM)
       dbm = gdbm_open (dbName_orig, 0, GDBM_READER, 0600, NULL);
 #elif defined(HAVE_NDBM)
-      dbm = dbm_open (dbName_orig, O_CREAT|O_RDWR, 0600);
+      dbm = dbm_open (dbName_orig, O_RDONLY, 0600);
 #elif defined(HAVE_LIBTC)
       dbm = tcbdbnew ();
-      if (!tcbdbopen (dbm, dbName_orig, BDBOWRITER | BDBOCREAT))
+      if (!tcbdbopen (dbm, dbName_orig, BDBOREADER | BDBONOLCK))
         {
           tcbdbdel (dbm);
           dbm = NULL;
@@ -629,7 +629,7 @@ ypxfr (char *map, char *source_host, cha
       dbm = dbm_open (dbName_temp, O_CREAT|O_RDWR, 0600);
 #elif defined(HAVE_LIBTC)
       dbm = tcbdbnew ();
-      if (!tcbdbopen (dbm, dbName_orig, BDBOWRITER | BDBOCREAT))
+      if (!tcbdbopen (dbm, dbName_orig, BDBOWRITER | BDBOCREAT | BDBOTRUNC))
         {
           tcbdbdel (dbm);
           dbm = NULL;
@@ -782,7 +782,12 @@ ypxfr (char *map, char *source_host, cha
     }
 
   if (result == 0)
-    rename (dbName_temp, dbName_orig);
+    {
+#if defined(HAVE_LIBTC)
+      chmod(dbName_temp, S_IRUSR|S_IWUSR);
+#endif
+      rename (dbName_temp, dbName_orig);
+    }
   else
     unlink(dbName_temp);