diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c
index 0c6e23f..d2288b9 100644
--- a/src/openvpnserv/interactive.c
+++ b/src/openvpnserv/interactive.c
@@ -2959,7 +2959,7 @@
         const char *rdom = msg->resolve_domains;
         size_t rdom_size = sizeof(msg->resolve_domains);
         size_t rdom_len = strlen(rdom);
-        if (rdom_len && (rdom_len + 1 >= rdom_size || rdom[rdom_len + 2] != 0))
+        if (rdom_len && (rdom_len + 1 >= rdom_size || rdom[rdom_len + 1] != 0))
         {
             return ERROR_MESSAGE_DATA;
         }