diff --git a/ChangeLog b/ChangeLog
index 095e87488f..8af2f57c43 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Mon Feb  6 16:38:56 2012  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/win32.c (unixtime_to_filetime): should check the return value
+	  of localtime().  reported by snowjail at gmail.com.
+	  [ruby-dev:44838] [Bug #5596]
+
 Mon Feb  6 16:36:25 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* io.c (rb_update_max_fd): fstat(2) can fail with other than
diff --git a/version.h b/version.h
index 496ecf66d5..25cccf6e7f 100644
--- a/version.h
+++ b/version.h
@@ -1,5 +1,5 @@
 #define RUBY_VERSION "1.9.3"
-#define RUBY_PATCHLEVEL 35
+#define RUBY_PATCHLEVEL 36
 
 #define RUBY_RELEASE_DATE "2012-02-06"
 #define RUBY_RELEASE_YEAR 2012
diff --git a/win32/win32.c b/win32/win32.c
index 759762b89a..977628126a 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -5460,6 +5460,9 @@ unixtime_to_filetime(time_t time, FILETIME *ft)
     FILETIME lt;
 
     tm = localtime(&time);
+    if (!tm) {
+	return -1;
+    }
     st.wYear = tm->tm_year + 1900;
     st.wMonth = tm->tm_mon + 1;
     st.wDayOfWeek = tm->tm_wday;