diff --git a/ChangeLog b/ChangeLog
index e20cd769bb..0d2268da00 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sun Nov 20 22:43:03 2011  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* enc/unicode.c (PROPERTY_NAME_MAX_SIZE): +1.
+	  reported by Ken Takata. [ruby-dev:44894][Bug #5652]
+
 Sun Nov 20 11:01:28 2011  Tanaka Akira  <akr@fsij.org>
 
 	* lib/set.rb (SortedSet.setup): remove old_init after initialize
diff --git a/enc/unicode.c b/enc/unicode.c
index beb5fa39f0..e7eb7b3902 100644
--- a/enc/unicode.c
+++ b/enc/unicode.c
@@ -2080,7 +2080,7 @@ onigenc_utf16_32_get_ctype_code_range(OnigCtype ctype, OnigCodePoint* sb_out,
 
 #include "ruby/st.h"
 
-#define PROPERTY_NAME_MAX_SIZE    MAX_WORD_LENGTH
+#define PROPERTY_NAME_MAX_SIZE    MAX_WORD_LENGTH+1
 
 extern int
 onigenc_unicode_property_name_to_ctype(OnigEncoding enc, UChar* name, UChar* end)