diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 02821fe..ef7aa0a 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -80,6 +80,7 @@
 
 #include "../../include/linux/perf_event.h"
 #include "util/types.h"
+#include <stdbool.h>
 
 /*
  * prctl(PR_TASK_PERF_EVENTS_DISABLE) will (cheaply) disable all
@@ -131,6 +132,6 @@
 	u64 ips[0];
 };
 
-extern int perf_host, perf_guest;
+extern bool perf_host, perf_guest;
 
 #endif