diff --git a/ChangeLog b/ChangeLog
index 1dba9d5846..74607fbc88 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed Jan 23 16:29:09 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* win32/win32.c (rb_w32_spawn, rb_w32_aspawn_flags): fix missing
+	  initialization.  pointed out by phasis68 (Heesob Park) at
+	  [ruby-core:51579].  [Bug #7721]
+
 Wed Jan 23 16:18:04 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/mkmf.rb (MakeMakefile#try_constant): fix for large unsigned.
diff --git a/win32/win32.c b/win32/win32.c
index 8b577eaf84..984e03b0dd 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -1184,7 +1184,7 @@ rb_w32_spawn(int mode, const char *cmd, const char *prog)
     const char *shell = NULL;
     WCHAR *wcmd = NULL, *wshell = NULL;
     int e = 0;
-    rb_pid_t ret;
+    rb_pid_t ret = -1;
     VALUE v = 0;
     VALUE v2 = 0;
 
@@ -1293,7 +1293,7 @@ rb_w32_aspawn_flags(int mode, const char *prog, char *const *argv, DWORD flags)
     char *cmd, fbuf[MAXPATHLEN];
     WCHAR *wcmd = NULL, *wprog = NULL;
     int e = 0;
-    rb_pid_t ret;
+    rb_pid_t ret = -1;
     VALUE v = 0;
 
     if (check_spawn_mode(mode)) return -1;