diff --git a/ChangeLog b/ChangeLog
index ff8e5f9ce0..7bbaab9ce0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Sep  8 22:15:33 2003    <nagai@ai.kyutech.ac.jp>
+
+	* multi-tk.rb: modify security check at creating a new interpreter
+
 Mon Sep  8 20:00:12 2003  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/optparse.rb, lib/optparse/version.rb: search also all
diff --git a/ext/tk/lib/multi-tk.rb b/ext/tk/lib/multi-tk.rb
index 7053dddef9..750a2b79d9 100644
--- a/ext/tk/lib/multi-tk.rb
+++ b/ext/tk/lib/multi-tk.rb
@@ -459,12 +459,20 @@ class MultiTkIp
   ######################################
 
   def initialize(master, safeip=true, keys={})
-    if safeip == nil && !master.master?
-      fail SecurityError, "slave-ip cannot create master-ip"
+    if $SAFE >= 4
+      fail SecurityError, "cannot create a new interpreter at level #{$SAFE}"
     end
 
-    if safeip == nil && $SAFE >= 4
-      fail SecurityError, "cannot create master-ip at level #{$SAFE}"
+    if safeip == nil && $SAFE >= 2
+      fail SecurityError, "cannot create a master-ip at level #{$SAFE}"
+    end
+
+    if !master.master? && master.safe?
+      fail SecurityError, "safe-slave-ip cannot create a new interpreter"
+    end
+
+    if safeip == nil && !master.master?
+      fail SecurityError, "slave-ip cannot create a master-ip"
     end
 
     unless keys.kind_of? Hash