--- libbridge/libbridge_private.h
+++ libbridge/libbridge_private.h
@@ -36,6 +36,11 @@
 
 extern int br_socket_fd;
 
+#include <unistd.h>
+#ifndef HZ
+# define HZ sysconf(_SC_CLK_TCK)
+#endif
+
 static inline unsigned long __tv_to_jiffies(const struct timeval *tv)
 {
 	unsigned long long jif;