diff --git a/test/zdtm/lib/lock.h b/test/zdtm/lib/lock.h
index 2b23550be5f..cc5306e0600 100644
--- a/test/zdtm/lib/lock.h
+++ b/test/zdtm/lib/lock.h
@@ -7,6 +7,7 @@
 #include <sys/time.h>
 #include <limits.h>
 #include <errno.h>
+#include <signal.h>
 #include "asm/atomic.h"
 
 #define BUG_ON(condition)                                                        \