diff --git a/ChangeLog b/ChangeLog
index 969666ce9b..2c9897e7a3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,4 +1,9 @@
-Mon Mar  2 10:50:53 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Mon Mar  2 11:01:45 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* ext/dl/dl.h (dlerror): fixed on Windows.
+
+	* ext/dl/handle.c (rb_dlhandle_initialize): returns handle to
+	  libruby if nil is given on Windows as dlopen.
 
 	* ext/dl/handle.c (rb_dlhandle_sym): get rid of buffer overrun,
 	  and try ASCII WINAPI versions too.
diff --git a/ext/dl/dl.h b/ext/dl/dl.h
index 753bd1c976..fb904bc561 100644
--- a/ext/dl/dl.h
+++ b/ext/dl/dl.h
@@ -24,7 +24,7 @@
 #   include <windows.h>
 #   define dlclose(ptr) FreeLibrary((HINSTANCE)ptr)
 #   define dlopen(name,flag) ((void*)LoadLibrary(name))
-#   define dlerror()    "unknown error"
+#   define dlerror() strerror(rb_w32_map_errno(GetLastError()))
 #   define dlsym(handle,name) ((void*)GetProcAddress(handle,name))
 #   define RTLD_LAZY -1
 #   define RTLD_NOW  -1
diff --git a/ext/dl/handle.c b/ext/dl/handle.c
index b8752004bc..c4ee0b9c14 100644
--- a/ext/dl/handle.c
+++ b/ext/dl/handle.c
@@ -67,6 +67,13 @@ rb_dlhandle_initialize(int argc, VALUE argv[], VALUE self)
     rb_bug("rb_dlhandle_new");
   }
 
+#if defined(HAVE_WINDOWS_H)
+  if( !clib ){
+    HANDLE rb_libruby_handle(void);
+    ptr = rb_libruby_handle();
+  }
+  else
+#endif
   ptr = dlopen(clib, cflag);
 #if defined(HAVE_DLERROR)
   if( !ptr && (err = dlerror()) ){
diff --git a/ruby.c b/ruby.c
index ab15cd979a..b9a8ce27a5 100644
--- a/ruby.c
+++ b/ruby.c
@@ -325,6 +325,12 @@ DllMain(HINSTANCE dll, DWORD reason, LPVOID reserved)
 	libruby = dll;
     return TRUE;
 }
+
+HANDLE
+rb_libruby_handle(void)
+{
+    return libruby;
+}
 #endif
 
 void ruby_init_loadpath_safe(int safe_level);