diff --git a/src/hb-private.hh b/src/hb-private.hh
index b13d9cd6f..c757e2dc9 100644
--- a/src/hb-private.hh
+++ b/src/hb-private.hh
@@ -29,7 +29,7 @@
 #ifndef HB_PRIVATE_HH
 #define HB_PRIVATE_HH
 
-#if HAVE_CONFIG_H
+#ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
diff --git a/src/hb-unicode-private.hh b/src/hb-unicode-private.hh
index dace9245f..2ad8a4984 100644
--- a/src/hb-unicode-private.hh
+++ b/src/hb-unicode-private.hh
@@ -90,10 +90,10 @@ struct _hb_unicode_funcs_t {
 };
 
 
-#if HAVE_GLIB
+#ifdef HAVE_GLIB
 extern HB_INTERNAL hb_unicode_funcs_t _hb_glib_unicode_funcs;
 #define _hb_unicode_funcs_default _hb_glib_unicode_funcs
-#elif HAVE_ICU
+#elif defined(HAVE_ICU)
 extern HB_INTERNAL hb_unicode_funcs_t _hb_icu_unicode_funcs;
 #define _hb_unicode_funcs_default _hb_icu_unicode_funcs
 #else
diff --git a/src/test.cc b/src/test.cc
index af6a45a31..bdf017c94 100644
--- a/src/test.cc
+++ b/src/test.cc
@@ -24,7 +24,7 @@
  * Google Author(s): Behdad Esfahbod
  */
 
-#if HAVE_CONFIG_H
+#ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
@@ -93,7 +93,7 @@ main (int argc, char **argv)
   hb_font_t *font = hb_font_create (face);
   hb_font_set_scale (font, upem, upem);
 
-#if HAVE_FREETYPE
+#ifdef HAVE_FREETYPE
   hb_ft_font_set_funcs (font);
 #endif
 
diff --git a/util/common.hh b/util/common.hh
index 1ce61af56..a9a16f469 100644
--- a/util/common.hh
+++ b/util/common.hh
@@ -41,7 +41,7 @@
 #include <locale.h>
 #include <errno.h>
 #include <fcntl.h>
-#if HAVE_IO_H
+#ifdef HAVE_IO_H
 #include <io.h> /* for _setmode() under Windows */
 #endif
 
diff --git a/util/options.cc b/util/options.cc
index 582e43711..a923a980c 100644
--- a/util/options.cc
+++ b/util/options.cc
@@ -26,7 +26,7 @@
 
 #include "options.hh"
 
-#if HAVE_FREETYPE
+#ifdef HAVE_FREETYPE
 #include <hb-ft.h>
 #endif
 
@@ -439,7 +439,7 @@ font_options_t::get_font (void) const
       /* read it */
       GString *gs = g_string_new (NULL);
       char buf[BUFSIZ];
-#if HAVE_IO_H
+#ifdef HAVE_IO_H
       _setmode (fileno (stdin), O_BINARY);
 #endif
       while (!feof (stdin)) {
@@ -498,7 +498,7 @@ font_options_t::get_font (void) const
   hb_font_set_scale (font, upem, upem);
   hb_face_destroy (face);
 
-#if HAVE_FREETYPE
+#ifdef HAVE_FREETYPE
   hb_ft_font_set_funcs (font);
 #endif
 
@@ -579,7 +579,7 @@ output_options_t::get_file_handle (void)
   if (output_file)
     fp = fopen (output_file, "wb");
   else {
-#if HAVE_IO_H
+#ifdef HAVE_IO_H
     _setmode (fileno (stdout), O_BINARY);
 #endif
     fp = stdout;