diff --git a/watch.c b/watch.c
index 747c4804..a6ad22e7 100644
--- a/watch.c
+++ b/watch.c
@@ -17,6 +17,7 @@
 #include "config.h"
 #include "nls.h"
 #include "proc/procps.h"
+#include "strutils.h"
 #include "xalloc.h"
 #include <ctype.h>
 #include <errno.h>