diff --git a/ChangeLog b/ChangeLog
index 46a4777f6a..0de1d664ed 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Mar  5 20:23:54 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* include/ruby/intern.h (rb_check_arity): make a static inline
+	  function so it can be used as an expression and argc would be
+	  evaulated only once.
+
 Tue Mar  5 12:30:55 2013  Eric Hodel  <drbrain@segment7.net>
 
 	* lib/rubygems.rb:  Bump version to 2.0.1 for upcoming bugfix release
diff --git a/include/ruby/intern.h b/include/ruby/intern.h
index 5ff17a4971..063c5d059e 100644
--- a/include/ruby/intern.h
+++ b/include/ruby/intern.h
@@ -266,10 +266,12 @@ const char *rb_sourcefile(void);
 VALUE rb_check_funcall(VALUE, ID, int, VALUE*);
 
 NORETURN(void rb_error_arity(int, int, int));
-#define rb_check_arity(argc, min, max) do { \
-  if (((argc) < (min)) || ((argc) > (max) && (max) != UNLIMITED_ARGUMENTS)) \
-    rb_error_arity(argc, min, max); \
-  } while(0)
+static inline void
+rb_check_arity(int argc, int min, int max)
+{
+    if ((argc < min) || (max != UNLIMITED_ARGUMENTS && argc > max))
+	rb_error_arity(argc, min, max);
+}
 
 #if defined(NFDBITS) && defined(HAVE_RB_FD_INIT)
 typedef struct {