diff --git a/ChangeLog b/ChangeLog
index 5acf7060cf..4663d1c22c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jul 30 23:28:10 2014  Kazuki Tsujimoto  <kazuki@callcc.net>
+
+	* sprintf.c (rb_str_format): like r47006, get rid of
+	  function calls in RSTRING_PTR().
+
 Wed Jul 30 22:10:29 2014  Kazuki Tsujimoto  <kazuki@callcc.net>
 
 	* process.c (rlimit_resource_type, rlimit_resource_value):
diff --git a/sprintf.c b/sprintf.c
index 3d2d6db4b6..c4f304fafc 100644
--- a/sprintf.c
+++ b/sprintf.c
@@ -602,8 +602,8 @@ rb_str_format(int argc, const VALUE *argv, VALUE fmt)
 #endif
 		len = (int)(p - start + 1); /* including parenthesis */
 		if (sym != Qnil) {
-		    rb_enc_raise(enc, rb_eArgError, "named%.*s after <%s>",
-				 len, start, RSTRING_PTR(rb_sym2str(sym)));
+		    rb_enc_raise(enc, rb_eArgError, "named%.*s after <%"PRIsVALUE">",
+				 len, start, rb_sym2str(sym));
 		}
 		CHECKNAMEARG(start, len, enc);
 		get_hash(&hash, argc, argv);