diff --git a/lib/connect.c b/lib/connect.c
index 826ec251d997c032142de178b17e6f5b712f9c0b..6a79e64de7b97236145a3f2c403b189e7763725d 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -94,7 +94,7 @@ static bool verifyconnect(curl_socket_t sockfd, int *error);
 #define KEEPALIVE_FACTOR(x)
 #endif
 
-#if defined(HAVE_WINSOCK_H) && !defined(SIO_KEEPALIVE_VALS)
+#if defined(HAVE_WINSOCK2_H) && !defined(SIO_KEEPALIVE_VALS)
 #define SIO_KEEPALIVE_VALS    _WSAIOW(IOC_VENDOR,4)
 
 struct tcp_keepalive {