diff --git a/src/core/org/luaj/vm2/LuaValue.java b/src/core/org/luaj/vm2/LuaValue.java
index 824804a4..93d8a490 100644
--- a/src/core/org/luaj/vm2/LuaValue.java
+++ b/src/core/org/luaj/vm2/LuaValue.java
@@ -107,7 +107,7 @@ public class LuaValue extends Varargs {
 	public Object  touserdata()          { return null; }
 	public Object  touserdata(Class c)   { return null; }
 
-	// object tojstring() maps to tojstring() 
+	// Object.toString() maps to tojstring() 
 	public String toString() { return tojstring(); }
 	
 	// type coercion to lua values
@@ -519,9 +519,6 @@ public class LuaValue extends Varargs {
 		public LuaValue arg1() { 
 			return v1; 
 		}
-		public String tojstring() {
-			return "{"+v1+","+v2+"}";
-		}
 	}
 
 
diff --git a/src/core/org/luaj/vm2/Varargs.java b/src/core/org/luaj/vm2/Varargs.java
index 85b6f282..41d2ebe1 100644
--- a/src/core/org/luaj/vm2/Varargs.java
+++ b/src/core/org/luaj/vm2/Varargs.java
@@ -143,6 +143,9 @@ public abstract class Varargs {
 		sb.append( ")" );
 		return sb.tojstring();
 	}
+	
+	// Object.toString() maps to tojstring() 
+	public String toString() { return tojstring(); }
 
 	public Varargs subargs(final int start) {
 		int end = narg();
diff --git a/src/core/org/luaj/vm2/lib/DebugLib.java b/src/core/org/luaj/vm2/lib/DebugLib.java
index b9be0376..5daf4465 100644
--- a/src/core/org/luaj/vm2/lib/DebugLib.java
+++ b/src/core/org/luaj/vm2/lib/DebugLib.java
@@ -22,9 +22,12 @@
 package org.luaj.vm2.lib;
 
 import org.luaj.vm2.Lua;
+import org.luaj.vm2.LuaBoolean;
 import org.luaj.vm2.LuaClosure;
 import org.luaj.vm2.LuaError;
 import org.luaj.vm2.LuaFunction;
+import org.luaj.vm2.LuaNil;
+import org.luaj.vm2.LuaNumber;
 import org.luaj.vm2.LuaString;
 import org.luaj.vm2.LuaTable;
 import org.luaj.vm2.LuaThread;
@@ -534,10 +537,15 @@ public class DebugLib extends OneArgFunction {
 	private static Varargs _setmetatable(Varargs args) {
 		LuaValue object = args.arg(1);
 		try {
-			if ( ! args.isnoneornil(2) )
-				object.setmetatable(args.checktable(2));
-			else
-				object.setmetatable(null);
+			LuaValue mt = args.opttable(2, null);
+			switch ( object.type() ) {
+				case TNIL:      LuaNil.s_metatable      = mt; break;
+				case TNUMBER:   LuaNumber.s_metatable   = mt; break;
+				case TBOOLEAN:  LuaBoolean.s_metatable  = mt; break;
+				case TSTRING:   LuaString.s_metatable   = mt; break;
+				case TFUNCTION: LuaFunction.s_metatable = mt; break;
+				default: object.setmetatable( mt );
+			}
 			return LuaValue.TRUE;
 		} catch ( LuaError e ) {
 			return varargsOf(FALSE, valueOf(e.toString()));
diff --git a/src/jse/lua.java b/src/jse/lua.java
index 38e8217f..4ec37f26 100644
--- a/src/jse/lua.java
+++ b/src/jse/lua.java
@@ -126,7 +126,7 @@ public class lua {
 					break;
 				} else if ( "-".equals( args[i] ) ) {
 					setGlobalArg( _G, args, i );
-					processScript( System.in, "stdin" );
+					processScript( System.in, "=stdin" );
 					break;
 				} else {
 					switch ( args[i].charAt(1) ) {
@@ -202,7 +202,7 @@ public class lua {
 			String line = reader.readLine();
 			if ( line == null )
 				return;
-			processScript( new ByteArrayInputStream(line.getBytes()), "stdin" );
+			processScript( new ByteArrayInputStream(line.getBytes()), "=stdin" );
 		}
 	}
 }
diff --git a/src/jse/luac.java b/src/jse/luac.java
index 3b431a2c..b6098efd 100644
--- a/src/jse/luac.java
+++ b/src/jse/luac.java
@@ -134,7 +134,7 @@ public class luac {
 						String chunkname = args[i].substring(0,args[i].length()-4);
 						processScript( new FileInputStream(args[i]), chunkname, fos );
 					} else if ( args[i].length() <= 1 ) {
-						processScript( System.in, "stdin", fos );
+						processScript( System.in, "=stdin", fos );
 					} else {
 						switch ( args[i].charAt(1) ) {
 						case 'o':
diff --git a/test/junit/org/luaj/vm2/ScriptDrivenTest.java b/test/junit/org/luaj/vm2/ScriptDrivenTest.java
index 2c328d65..1ba7bbf2 100644
--- a/test/junit/org/luaj/vm2/ScriptDrivenTest.java
+++ b/test/junit/org/luaj/vm2/ScriptDrivenTest.java
@@ -60,7 +60,7 @@ public class ScriptDrivenTest extends TestCase {
 			default:
 			case JSE:
 			case LUAJIT:
-				_G = org.luaj.vm2.lib.JsePlatform.standardGlobals();
+				_G = org.luaj.vm2.lib.JsePlatform.debugGlobals();
 				break;
 			case JME:
 				_G = org.luaj.vm2.lib.JmePlatform.debugGlobals();
@@ -115,7 +115,7 @@ public class ScriptDrivenTest extends TestCase {
 				}
 			default:
 				script = new FileInputStream(file);
-				return LoadState.load(script, "stdin", _G);
+				return LoadState.load(script, "=stdin", _G);
 			}
 		} catch ( Exception e ) {
 			e.printStackTrace();
diff --git a/test/junit/org/luaj/vm2/vm1/Luajvm1CompatibilityTest.java b/test/junit/org/luaj/vm2/vm1/Luajvm1CompatibilityTest.java
index 86f94bd4..0c3609f4 100644
--- a/test/junit/org/luaj/vm2/vm1/Luajvm1CompatibilityTest.java
+++ b/test/junit/org/luaj/vm2/vm1/Luajvm1CompatibilityTest.java
@@ -92,7 +92,7 @@ public class Luajvm1CompatibilityTest extends TestCase {
 		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
 		PrintStream printStream = new PrintStream( outputStream );
 		try {
-			org.luaj.vm2.LuaTable _G = org.luaj.vm2.lib.JsePlatform.standardGlobals();
+			org.luaj.vm2.LuaTable _G = org.luaj.vm2.lib.JsePlatform.debugGlobals();
 			LuaThread.getRunning().setfenv(_G);
 			_G.get("package").get("loaders").checktable().insert(1, new org.luaj.vm2.lib.OneArgFunction(_G) {
 				public LuaValue call(LuaValue arg) {
diff --git a/test/junit/org/luaj/vm2/vm1/luajvm1-tests.zip b/test/junit/org/luaj/vm2/vm1/luajvm1-tests.zip
index 2e28ab7e..19e4fca5 100644
Binary files a/test/junit/org/luaj/vm2/vm1/luajvm1-tests.zip and b/test/junit/org/luaj/vm2/vm1/luajvm1-tests.zip differ
diff --git a/test/lua/debuglib.lua b/test/lua/debuglib.lua
index 8fd18b0e..b858d98a 100644
--- a/test/lua/debuglib.lua
+++ b/test/lua/debuglib.lua
@@ -114,8 +114,8 @@ print( 'get='..tostring(s4)..','..tostring(x4==nil)..','..tostring(y4) )
 print( 'set='..tostring(s5)..','..tostring(x5==a)..','..tostring(y5) ) 
 print( 'get='..tostring(s6)..','..tostring(x6==nil)..','..tostring(y6) ) 
 print( pcall( debug.getmetatable, 1 ) )
--- print( pcall( debug.setmetatable, 1, {} ) )
--- print( pcall( debug.setmetatable, 1, nil ) )
+print( pcall( debug.setmetatable, 1, {} ) )
+print( pcall( debug.setmetatable, 1, nil ) )
 
 print( '----- debug.getinfo' )
 local printfield = function(tbl, field)
@@ -126,10 +126,6 @@ local printfield = function(tbl, field)
 		x = '{'..table.concat(x,',')..'}'
 	elseif typ=='function' then
 		x = typ
-	elseif typ=='string' then
-		if field == 'source' then 
-			x = x:sub(2)
-		end
 	end
 	print( '    '..field..': '..tostring(x) )
 end