Don't use NULL in public headers
diff --git a/src/hb-buffer.h b/src/hb-buffer.h
index 42564bb..a8a4b84 100644
--- a/src/hb-buffer.h
+++ b/src/hb-buffer.h
@@ -132,8 +132,8 @@
#define HB_SEGMENT_PROPERTIES_DEFAULT {HB_DIRECTION_INVALID, \
HB_SCRIPT_INVALID, \
HB_LANGUAGE_INVALID, \
- NULL, \
- NULL}
+ (void *) 0, \
+ (void *) 0}
HB_EXTERN hb_bool_t
hb_segment_properties_equal (const hb_segment_properties_t *a,
diff --git a/src/hb-common.h b/src/hb-common.h
index 614a63a..26200ce 100644
--- a/src/hb-common.h
+++ b/src/hb-common.h
@@ -134,7 +134,7 @@
HB_EXTERN const char *
hb_language_to_string (hb_language_t language);
-#define HB_LANGUAGE_INVALID ((hb_language_t) NULL)
+#define HB_LANGUAGE_INVALID ((hb_language_t) 0)
HB_EXTERN hb_language_t
hb_language_get_default (void);
