diff --git a/mptcp_mode.c b/mptcp_mode.c
index e61b5b4..a2c8e8c 100644
--- a/mptcp_mode.c
+++ b/mptcp_mode.c
@@ -35,7 +35,7 @@ int socket(int domain, int type, int protocol)
 {
     _mptcpmode_load();
 
-    if (((PF_INET == domain) || (PF_INET6 == domain))
+    if (((IPPROTO_TCP == protocol) || (0 == protocol))
         && (SOCK_STREAM == type)) {
 
 #ifdef DEBUG