diff --git a/ChangeLog b/ChangeLog
index 9a593449d3..3f5380a360 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+Thu Sep  4 17:44:40 2014  Koichi Sasada  <ko1@atdot.net>
+
+	* dir.c (glob_helper): use #ifdef instead of #if.
+	  gcc's -Wundef option shows warning for undefined macro.
+
+	* numeric.c (flo_is_finite_p): ditto.
+
+	* vm_dump.c (rb_vmdebug_thread_dump_state): ditto.
+
+	* vm_core.h: define VM_DEBUG_VERIFY_METHOD_CACHE to 0.
+
 Thu Sep  4 03:57:46 2014  Eric Wong  <e@80x24.org>
 
 	* man/ruby.1: spelling fix ("bellow" => "below") [ci-skip]
diff --git a/dir.c b/dir.c
index e99adedaa9..b915c4be41 100644
--- a/dir.c
+++ b/dir.c
@@ -1405,11 +1405,11 @@ glob_helper(
     if (magical || recursive) {
 	struct dirent *dp;
 	DIR *dirp;
-# if DOSISH
+# ifdef DOSISH
 	char *plainname = 0;
 # endif
 	IF_HAVE_HFS(int hfs_p);
-# if DOSISH
+# ifdef DOSISH
 	if (cur + 1 == end && (*cur)->type <= ALPHA) {
 	    plainname = join_path(path, pathlen, dirsep, (*cur)->str, strlen((*cur)->str));
 	    if (!plainname) return -1;
diff --git a/numeric.c b/numeric.c
index 1e971f41ea..2fdfaafda0 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1488,7 +1488,7 @@ flo_is_finite_p(VALUE num)
 {
     double value = RFLOAT_VALUE(num);
 
-#if HAVE_ISFINITE
+#ifdef HAVE_ISFINITE
     if (!isfinite(value))
 	return Qfalse;
 #else
diff --git a/vm_core.h b/vm_core.h
index e828e917ba..1afa1b2914 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -474,6 +474,10 @@ typedef struct rb_vm_struct {
 #define VM_DEBUG_BP_CHECK 0
 #endif
 
+#ifndef VM_DEBUG_VERIFY_METHOD_CACHE
+#define VM_DEBUG_VERIFY_METHOD_CACHE 0
+#endif
+
 typedef struct rb_control_frame_struct {
     VALUE *pc;			/* cfp[0] */
     VALUE *sp;			/* cfp[1] */
diff --git a/vm_dump.c b/vm_dump.c
index 2ed3f1431b..bb2b2415c4 100644
--- a/vm_dump.c
+++ b/vm_dump.c
@@ -432,7 +432,7 @@ rb_vmdebug_thread_dump_state(VALUE self)
 }
 
 #if defined(HAVE_BACKTRACE)
-# if HAVE_LIBUNWIND
+# ifdef HAVE_LIBUNWIND
 #  undef backtrace
 #  define backtrace unw_backtrace
 # elif defined(__APPLE__) && defined(__x86_64__)