1 files changed, 5 insertions, 0 deletions
diff --git a/util.h b/util.h
index 2992bea..b2446a7 100644
--- a/util.h
+++ b/util.h
@@ -1,3 +1,6 @@
+#ifndef UTIL_H
+#define UTIL_H
+
 #define LENGTH(x)  ((int)(sizeof (x) / sizeof *(x)))
 #define MIN(a, b)  ((a) > (b) ? (b) : (a))
 #define MAX(a, b)  ((a) < (b) ? (b) : (a))
@@ -5,3 +8,5 @@
 /* is c the start of a utf8 sequence? */
 #define isutf8(c) (((c)&0xC0)!=0x80)
 #define ISASCII(ch)   ((unsigned char)ch < 0x80)
+
+#endif