diff --git a/libexec/rpc.rusersd/rusers_proc.c b/libexec/rpc.rusersd/rusers_proc.c
index 71ccb9ebc793..8bd96924b29a 100644
--- a/libexec/rpc.rusersd/rusers_proc.c
+++ b/libexec/rpc.rusersd/rusers_proc.c
@@ -43,6 +43,7 @@ static const char rcsid[] =
 #include <string.h>
 #include <sys/param.h>
 #include <sys/stat.h>
+#include <stdlib.h>
 #include <syslog.h>
 #include <utmp.h>
 #ifdef XIDLE