diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c
index d58defcc42..49b72131d8 100644
--- a/src/cryptsetup/cryptsetup.c
+++ b/src/cryptsetup/cryptsetup.c
@@ -234,7 +234,7 @@ static int parse_one_option(const char *option) {
                         return log_oom();
 
         } else if ((val = startswith(option, "header="))) {
-                if (!STR_IN_SET(arg_type, ANY_LUKS, CRYPT_LUKS1, CRYPT_LUKS2, CRYPT_TCRYPT))
+                if (!arg_type || !STR_IN_SET(arg_type, ANY_LUKS, CRYPT_LUKS1, CRYPT_LUKS2, CRYPT_TCRYPT))
                         arg_type = ANY_LUKS;
 
                 if (!path_is_absolute(val))