diff --git a/ChangeLog b/ChangeLog
index bfe08fbb9b..fb70f0448e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Feb 22 21:45:56 2012  Tanaka Akira  <akr@fsij.org>
+
+	* ext/curses/curses.c: use defined() to suppress a warning.
+
 Wed Feb 22 21:44:29 2012  Tanaka Akira  <akr@fsij.org>
 
 	* ext/curses/extconf.rb: refactored.
diff --git a/ext/curses/curses.c b/ext/curses/curses.c
index 60ba65b15b..4efa4c1db6 100644
--- a/ext/curses/curses.c
+++ b/ext/curses/curses.c
@@ -2768,9 +2768,9 @@ Init_curses(void)
     rb_define_module_function(mCurses, "def_prog_mode", curses_def_prog_mode, 0);
     rb_define_module_function(mCurses, "reset_prog_mode", curses_reset_prog_mode, 0);
 
-#ifdef HAVE_FUNC_CURSES_VERSION
+#if defined(HAVE_FUNC_CURSES_VERSION)
     rb_define_const(mCurses, "VERSION", rb_str_new2(curses_version()));
-#elif HAVE_VAR_CURSES_VERSION
+#elif defined(HAVE_VAR_CURSES_VERSION)
     {
         /* SVR4 curses has an undocumented and undeclared variable, curses_version. */
         RUBY_EXTERN char *curses_version;