diff --git a/src/openvpnserv/interactive.c b/src/openvpnserv/interactive.c
index e2f17f0..484f27c 100644
--- a/src/openvpnserv/interactive.c
+++ b/src/openvpnserv/interactive.c
@@ -2217,7 +2217,7 @@
                 s--;
             }
 
-            if (inet_ntop(AF_INET6, &in_addrs[i], pos, s) != NULL)
+            if (inet_ntop(AF_INET6, &in_addrs[i], pos, s) == NULL)
             {
                 *size = 0;
                 return ERROR_MORE_DATA;