diff --git a/ChangeLog b/ChangeLog
index 5f6305cf6a..e869d9a8ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Mon Jun  1 10:41:41 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/intern.h (rb_exc_new2): optimization for literal.
+
 Mon Jun  1 07:20:02 2009  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* ext/bigdecimal/bigdecimal.c (BigDecimal_to_f): returns Inf if
diff --git a/error.c b/error.c
index 07a72a9a94..bfa3a950db 100644
--- a/error.c
+++ b/error.c
@@ -348,6 +348,8 @@ VALUE rb_eSystemCallError;
 VALUE rb_mErrno;
 static VALUE rb_eNOERROR;
 
+#undef rb_exc_new2
+
 VALUE
 rb_exc_new(VALUE etype, const char *ptr, long len)
 {
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index ec6527fc3a..08229f589d 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -693,6 +693,12 @@ size_t rb_str_capacity(VALUE);
 	rb_str_cat(str, ptr, strlen(ptr)) :	\
 	rb_str_cat2(str, ptr);			\
 })
+#define rb_exc_new2(klass, ptr) __extension__ ( \
+{						\
+    (__builtin_constant_p(ptr)) ?	        \
+	rb_exc_new(klass, ptr, strlen(ptr)) :	\
+	rb_exc_new2(klass, ptr);		\
+})
 #endif
 #define rb_str_new2 rb_str_new_cstr
 #define rb_str_new3 rb_str_new_shared