diff --git a/ChangeLog b/ChangeLog
index bde2467f2e..4f2837f4d9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul 18 14:37:57 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* string.c (str_alloc): no need to clear RString (already cleared).
+
 Thu Jul 18 12:57:47 2013  Tanaka Akira  <akr@fsij.org>
 
 	* bignum.c (BDIGITS_ZERO): Defined.
diff --git a/string.c b/string.c
index 2e1147adb3..05a97b47e7 100644
--- a/string.c
+++ b/string.c
@@ -382,11 +382,6 @@ static inline VALUE
 str_alloc(VALUE klass)
 {
     NEWOBJ_OF(str, struct RString, klass, T_STRING | (RGENGC_WB_PROTECTED_STRING ? FL_WB_PROTECTED : 0));
-
-    str->as.heap.ptr = 0;
-    str->as.heap.len = 0;
-    str->as.heap.aux.capa = 0;
-
     return (VALUE)str;
 }