diff --git a/ChangeLog b/ChangeLog
index b343b57769..ce51937e29 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Jul 19 22:47:29 2005  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* error.c (syserr_initialize): need to allocate an additional byte
+	  for NUL at the end.  [ruby-dev:26574]
+
 Tue Jul 19 17:16:34 2005  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* signal.c (trap): remove sigexit(); handle "EXIT" via sig_exec().
diff --git a/error.c b/error.c
index dc3ed1b358..347bacd5e0 100644
--- a/error.c
+++ b/error.c
@@ -956,7 +956,7 @@ syserr_initialize(argc, argv, self)
     else err = "unknown error";
     if (!NIL_P(mesg)) {
 	VALUE str = mesg;
-	size_t len = strlen(err)+RSTRING(str)->len+3;
+	size_t len = strlen(err)+RSTRING(str)->len+4;
 	StringValue(str);
 	mesg = rb_str_new(0, len);
 	snprintf(RSTRING(mesg)->ptr, len, "%s - %.*s", err,
diff --git a/eval.c b/eval.c
index eb5ea2758c..1824790956 100644
--- a/eval.c
+++ b/eval.c
@@ -8667,7 +8667,7 @@ proc_to_s(self)
     NODE *node;
     char *cname = rb_obj_classname(self);
     const int w = (SIZEOF_LONG * CHAR_BIT) / 4;
-    long len = strlen(cname)+6+w; /* 6:tags 16:addr */
+    long len = strlen(cname)+6+w+1; /* 6:tags 16:addr NUL */
     VALUE str;
 
     Data_Get_Struct(self, struct BLOCK, data);