diff --git a/ChangeLog b/ChangeLog
index 80194ce195..3d51db0fbe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Thu Sep 30 16:11:08 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/win32.c (rb_w32_getenv): should return NULL if specified name
+	  is empty. a patch from Heesob Park at [ruby-core:32650]
+
 Thu Sep 30 10:55:38 2010  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* hash.c (ruby_setenv): workaround for old Windows. a patch from
diff --git a/test/ruby/test_env.rb b/test/ruby/test_env.rb
index 97bf8fa476..681b21d614 100644
--- a/test/ruby/test_env.rb
+++ b/test/ruby/test_env.rb
@@ -96,6 +96,7 @@ class TestEnv < Test::Unit::TestCase
     assert_raise(ArgumentError) { ENV["foo\0bar"] }
     ENV[PATH_ENV] = ""
     assert_equal("", ENV[PATH_ENV])
+    assert_nil(ENV[""])
   end
 
   def test_fetch
diff --git a/win32/win32.c b/win32/win32.c
index 631b3e24e1..2dd9d0e023 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -3900,8 +3900,8 @@ rb_w32_getenv(const char *name)
     int len = strlen(name);
     char *env;
 
-    if (envarea)
-	FreeEnvironmentStrings(envarea);
+    if (len == 0) return NULL;
+    if (envarea) FreeEnvironmentStrings(envarea);
     envarea = GetEnvironmentStrings();
     if (!envarea) {
 	map_errno(GetLastError());