diff --git a/CHANGELOG b/CHANGELOG
index 94d428fa..f826cfb7 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -204,6 +204,11 @@ HISTORY
 
   ++ Bug fixes:
 
+  2007-06-13 Simon Goldschmidt
+  * api_msg.c: pcb_new sets conn->err if protocol is not implemented
+    -> netconn_new_..() does not allocate a new connection for unsupported
+    protocols.
+
   2007-06-13 Frédéric Bernon, Simon Goldschmidt
   * api_lib.c: change return expression in netconn_addr and netconn_peer, because
     conn->err was reset to ERR_OK without any reasons (and error was lost)...
diff --git a/src/api/api_msg.c b/src/api/api_msg.c
index f3093bc8..8985e919 100644
--- a/src/api/api_msg.c
+++ b/src/api/api_msg.c
@@ -326,6 +326,8 @@ pcb_new(struct api_msg_msg *msg)
      break;
 #endif /* LWIP_TCP */
    default:
+     /* Unsupported netconn type, e.g. protocol disabled */
+     msg->conn->err = ERR_VAL;
      break;
    }