diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c
index a5cf4c2c19..ded6c44778 100644
--- a/src/nspawn/nspawn.c
+++ b/src/nspawn/nspawn.c
@@ -4134,8 +4134,8 @@ static int make_uid_map_string(
          * quadruplet, consisting of host and container UID + GID. */
 
         for (size_t i = 0; i < n_bind_user_uid; i++) {
-                uid_t payload_uid = bind_user_uid[i*2+offset],
-                        host_uid = bind_user_uid[i*2+offset+1];
+                uid_t payload_uid = bind_user_uid[i*4+offset],
+                        host_uid = bind_user_uid[i*4+offset+1];
 
                 assert(previous_uid <= payload_uid);
                 assert(payload_uid < arg_uid_range);