diff --git a/test/unit/api/test_sockets.c b/test/unit/api/test_sockets.c
index 1fbac647..f21e0370 100644
--- a/test/unit/api/test_sockets.c
+++ b/test/unit/api/test_sockets.c
@@ -7,15 +7,10 @@
 
 
 /* Setups/teardown functions */
-static int tcpip_init_called;
 
 static void
 sockets_setup(void)
 {
-  if (!tcpip_init_called) {
-    tcpip_init_called = 1;
-    tcpip_init(NULL, NULL);
-  }
 }
 
 static void
@@ -27,6 +22,7 @@ sockets_teardown(void)
 #define NUM_SOCKETS MEMP_NUM_NETCONN
 #endif
 
+#if LWIP_SOCKET
 static int
 test_sockets_alloc_socket_nonblocking(int domain, int type)
 {
@@ -95,10 +91,14 @@ static void test_sockets_allfunctions_basic_domain(int domain)
   if (domain == AF_INET) {
 #if LWIP_IPV4
     struct sockaddr_in *addr4 = (struct sockaddr_in *)&addr;
-    addr4->sin_addr.s_addr = inet_addr("127.0.0.1");
+    addr4->sin_addr.s_addr = PP_HTONL(INADDR_LOOPBACK);
 #endif
   } else {
 #if LWIP_IPV6
+    struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&addr;
+    struct in6_addr lo6 = IN6ADDR_LOOPBACK_INIT;
+    addr6->sin6_addr = lo6;
+    //addr6->sin6_family = AF_INET6; /* TODO: fixme! */
 #endif
   }
   ret = lwip_connect(s2, (struct sockaddr*)&addr, addrlen);
@@ -208,6 +208,9 @@ static void test_sockets_sendmsg_udp(int domain)
     }
       break;
 #endif /* LWIP_IPV4 */
+    default:
+      fail();
+      break;
   }
 
   s = test_sockets_alloc_socket_nonblocking(domain, SOCK_DGRAM);
@@ -230,6 +233,9 @@ static void test_sockets_sendmsg_udp(int domain)
         fail_unless(addr_size == sizeof(struct sockaddr_in));
         break;
 #endif /* LWIP_IPV6 */
+    default:
+      fail();
+      break;
   }
 
   msg.msg_iov = iovs;
@@ -280,3 +286,12 @@ sockets_suite(void)
   };
   return create_suite("SOCKETS", tests, sizeof(tests)/sizeof(testfunc), sockets_setup, sockets_teardown);
 }
+
+#else /* LWIP_SOCKET */
+
+Suite *
+sockets_suite(void)
+{
+  return create_suite("SOCKETS", NULL, 0, NULL, NULL);
+}
+#endif /* LWIP_SOCKET */
diff --git a/test/unit/arch/sys_arch.c b/test/unit/arch/sys_arch.c
index b4a6f904..564a6bbc 100644
--- a/test/unit/arch/sys_arch.c
+++ b/test/unit/arch/sys_arch.c
@@ -33,20 +33,12 @@
 
 #include <lwip/opt.h>
 #include <lwip/arch.h>
-#include "sys_arch.h"
 #include <lwip/stats.h>
 #include <lwip/debug.h>
 #include <lwip/sys.h>
 
 #include <string.h>
 
-test_sys_arch_waiting_fn the_waiting_fn;
-
-void test_sys_arch_wait_callback(test_sys_arch_waiting_fn waiting_fn)
-{
-  the_waiting_fn = waiting_fn;
-}
-
 u32_t sys_jiffies(void)
 {
   return (u32_t)0; /* todo */
@@ -62,6 +54,14 @@ void sys_init(void)
 }
 
 #if !NO_SYS
+#include "sys_arch.h"
+
+test_sys_arch_waiting_fn the_waiting_fn;
+
+void test_sys_arch_wait_callback(test_sys_arch_waiting_fn waiting_fn)
+{
+  the_waiting_fn = waiting_fn;
+}
 
 err_t sys_sem_new(sys_sem_t *sem, u8_t count)
 {
diff --git a/test/unit/lwip_unittests.c b/test/unit/lwip_unittests.c
index 4f3dd1eb..48f3b6f7 100644
--- a/test/unit/lwip_unittests.c
+++ b/test/unit/lwip_unittests.c
@@ -11,6 +11,9 @@
 #include "api/test_sockets.h"
 
 #include "lwip/init.h"
+#if !NO_SYS
+#include "lwip/tcpip.h"
+#endif
 
 Suite* create_suite(const char* name, testfunc *tests, size_t num_tests, SFun setup, SFun teardown)
 {
@@ -51,7 +54,11 @@ int main(void)
   size_t num = sizeof(suites)/sizeof(void*);
   LWIP_ASSERT("No suites defined", num > 0);
 
+#if NO_SYS
   lwip_init();
+#else
+  tcpip_init(NULL, NULL);
+#endif
 
   sr = srunner_create((suites[0])());
   for(i = 1; i < num; i++) {
diff --git a/test/unit/lwipopts.h b/test/unit/lwipopts.h
index fd9adde8..433ea9db 100644
--- a/test/unit/lwipopts.h
+++ b/test/unit/lwipopts.h
@@ -32,12 +32,14 @@
 #ifndef LWIP_HDR_LWIPOPTS_H
 #define LWIP_HDR_LWIPOPTS_H
 
+#define LWIP_IPV6                       1
+
 /* We link to special sys_arch.c (for basic non-waiting API layers unit tests) */
 #define NO_SYS                          0
 #define SYS_LIGHTWEIGHT_PROT            0
-#define LWIP_NETCONN                    1
-#define LWIP_SOCKET                     1
-#define LWIP_NETCONN_FULLDUPLEX         1
+#define LWIP_NETCONN                    !NO_SYS
+#define LWIP_SOCKET                     !NO_SYS
+#define LWIP_NETCONN_FULLDUPLEX         LWIP_SOCKET
 #define LWIP_HAVE_LOOPIF                1
 #define TCPIP_THREAD_TEST