diff --git a/src/ckpasswd.c b/src/ckpasswd.c
index e3fed82..9dbdbcf 100644
--- a/src/ckpasswd.c
+++ b/src/ckpasswd.c
@@ -30,6 +30,7 @@
 #include <fcntl.h>
 #include <pwd.h>
 #include <grp.h>
+#include <getopt.h>
 
 #define DB_DBM_HSEARCH 1
 #include <db.h>