diff --git a/minix/lib/libc/sys/accept.c b/minix/lib/libc/sys/accept.c
index 6207f233a..e1eeed821 100644
--- a/minix/lib/libc/sys/accept.c
+++ b/minix/lib/libc/sys/accept.c
@@ -60,7 +60,7 @@ int accept(int sock, struct sockaddr *__restrict address,
 	nwio_udpopt_t udpopt;
 
 	r = __accept(sock, address, address_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= _tcp_accept(sock, address, address_len);
diff --git a/minix/lib/libc/sys/bind.c b/minix/lib/libc/sys/bind.c
index ddefa6ad1..d7c9a7495 100644
--- a/minix/lib/libc/sys/bind.c
+++ b/minix/lib/libc/sys/bind.c
@@ -58,7 +58,7 @@ int bind(int sock, const struct sockaddr *address, socklen_t address_len)
 	struct sockaddr_un uds_addr;
 
 	r = __bind(sock, address, address_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOGTCPCONF, &tcpconf);
diff --git a/minix/lib/libc/sys/connect.c b/minix/lib/libc/sys/connect.c
index be494845f..9d542beb4 100644
--- a/minix/lib/libc/sys/connect.c
+++ b/minix/lib/libc/sys/connect.c
@@ -57,7 +57,7 @@ int connect(int sock, const struct sockaddr *address,
 	nwio_udpopt_t udpopt;
 
 	r = __connect(sock, address, address_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOGTCPCONF, &tcpconf);
diff --git a/minix/lib/libc/sys/getpeername.c b/minix/lib/libc/sys/getpeername.c
index f79303406..975e3a924 100644
--- a/minix/lib/libc/sys/getpeername.c
+++ b/minix/lib/libc/sys/getpeername.c
@@ -60,7 +60,7 @@ int getpeername(int sock, struct sockaddr *__restrict address,
 	struct sockaddr_un uds_addr;
 
 	r = __getpeername(sock, address, address_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOGTCPCONF, &tcpconf);
diff --git a/minix/lib/libc/sys/getsockname.c b/minix/lib/libc/sys/getsockname.c
index e021185fe..23b1de92f 100644
--- a/minix/lib/libc/sys/getsockname.c
+++ b/minix/lib/libc/sys/getsockname.c
@@ -62,7 +62,7 @@ int getsockname(int fd, struct sockaddr *__restrict address,
 	struct sockaddr_un uds_addr;
 
 	r = __getsockname(fd, address, address_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 #if DEBUG
diff --git a/minix/lib/libc/sys/getsockopt.c b/minix/lib/libc/sys/getsockopt.c
index 7a1d1cf50..7edea530e 100644
--- a/minix/lib/libc/sys/getsockopt.c
+++ b/minix/lib/libc/sys/getsockopt.c
@@ -68,7 +68,7 @@ int getsockopt(int sock, int level, int option_name,
 	struct sockaddr_un uds_addr;
 
 	r = __getsockopt(sock, level, option_name, option_value, option_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOGTCPOPT, &tcpopt);
diff --git a/minix/lib/libc/sys/listen.c b/minix/lib/libc/sys/listen.c
index d0ac51439..a2522af90 100644
--- a/minix/lib/libc/sys/listen.c
+++ b/minix/lib/libc/sys/listen.c
@@ -35,7 +35,7 @@ int listen(int sock, int backlog)
 	int r;
 
 	r = __listen(sock, backlog);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOTCPLISTENQ, &backlog);
diff --git a/minix/lib/libc/sys/recvfrom.c b/minix/lib/libc/sys/recvfrom.c
index f04c627e6..47f508486 100644
--- a/minix/lib/libc/sys/recvfrom.c
+++ b/minix/lib/libc/sys/recvfrom.c
@@ -81,7 +81,7 @@ ssize_t recvfrom(int sock, void *__restrict buffer, size_t length,
 	int uds_sotype = -1;
 
 	r = __recvfrom(sock, buffer, length, flags, address, address_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 #if DEBUG
diff --git a/minix/lib/libc/sys/recvmsg.c b/minix/lib/libc/sys/recvmsg.c
index 18ea01cf2..d8c32e504 100644
--- a/minix/lib/libc/sys/recvmsg.c
+++ b/minix/lib/libc/sys/recvmsg.c
@@ -90,7 +90,7 @@ ssize_t recvmsg(int sock, struct msghdr *msg, int flags)
 	int uds_sotype;
 
 	r = __recvmsg(sock, msg, flags);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	if (msg == NULL) {
diff --git a/minix/lib/libc/sys/sendmsg.c b/minix/lib/libc/sys/sendmsg.c
index abfdfec47..4d4452cff 100644
--- a/minix/lib/libc/sys/sendmsg.c
+++ b/minix/lib/libc/sys/sendmsg.c
@@ -88,7 +88,7 @@ ssize_t sendmsg(int sock, const struct msghdr *msg, int flags)
 	int uds_sotype;
 
 	r = __sendmsg(sock, msg, flags);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	if (msg == NULL) {
diff --git a/minix/lib/libc/sys/sendto.c b/minix/lib/libc/sys/sendto.c
index ff83d8f7e..77304f301 100644
--- a/minix/lib/libc/sys/sendto.c
+++ b/minix/lib/libc/sys/sendto.c
@@ -63,7 +63,7 @@ ssize_t sendto(int sock, const void *message, size_t length, int flags,
 	int uds_sotype = -1;
 
 	r = __sendto(sock, message, length, flags, dest_addr, dest_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOGTCPOPT, &tcpopt);
diff --git a/minix/lib/libc/sys/setsockopt.c b/minix/lib/libc/sys/setsockopt.c
index 8ab1dcac8..04c0d311d 100644
--- a/minix/lib/libc/sys/setsockopt.c
+++ b/minix/lib/libc/sys/setsockopt.c
@@ -56,7 +56,7 @@ int setsockopt(int sock, int level, int option_name,
 	struct sockaddr_un uds_addr;
 
 	r = __setsockopt(sock, level, option_name, option_value, option_len);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOGTCPOPT, &tcpopt);
diff --git a/minix/lib/libc/sys/shutdown.c b/minix/lib/libc/sys/shutdown.c
index f0839f486..e2eaf8384 100644
--- a/minix/lib/libc/sys/shutdown.c
+++ b/minix/lib/libc/sys/shutdown.c
@@ -40,7 +40,7 @@ int shutdown(int sock, int how)
 	nwio_tcpconf_t tcpconf;
 
 	r = __shutdown(sock, how);
-	if (r != -1 || errno != ENOTSOCK)
+	if (r != -1 || (errno != ENOTSOCK && errno != ENOSYS))
 		return r;
 
 	r= ioctl(sock, NWIOGTCPCONF, &tcpconf);
diff --git a/minix/lib/libc/sys/socket.c b/minix/lib/libc/sys/socket.c
index e07f4ba13..ce2352a2b 100644
--- a/minix/lib/libc/sys/socket.c
+++ b/minix/lib/libc/sys/socket.c
@@ -60,7 +60,7 @@ int socket(int domain, int type, int protocol)
 	int r, sock_type;
 
 	r = __socket(domain, type, protocol);
-	if (r != -1 || errno != EAFNOSUPPORT)
+	if (r != -1 || (errno != EAFNOSUPPORT && errno != ENOSYS))
 		return r;
 
 	sock_type = type & ~SOCK_FLAGS_MASK;
diff --git a/minix/lib/libc/sys/socketpair.c b/minix/lib/libc/sys/socketpair.c
index 5f4a84460..1b1767dcd 100644
--- a/minix/lib/libc/sys/socketpair.c
+++ b/minix/lib/libc/sys/socketpair.c
@@ -45,7 +45,7 @@ socketpair(int domain, int type, int protocol, int sv[2])
 	int r;
 
 	r = __socketpair(domain, type, protocol, sv);
-	if (r != -1 || errno != EAFNOSUPPORT)
+	if (r != -1 || (errno != EAFNOSUPPORT && errno != ENOSYS))
 		return r;
 
 #if DEBUG