diff --git a/src/sys/include/net/arch/cc.h b/src/sys/include/net/arch/cc.h
index bb4d2ce..01dfe86 100644
--- a/src/sys/include/net/arch/cc.h
+++ b/src/sys/include/net/arch/cc.h
@@ -8,4 +8,8 @@
 #define PACK_STRUCT_BEGIN
 #define PACK_STRUCT_END
 
+#ifdef LWIP_ERR_T
+typedef uint8_t err_t;
+#endif
+
 #endif
diff --git a/src/sys/include/net/lwipopts.h b/src/sys/include/net/lwipopts.h
index 0abac09..76fd485 100644
--- a/src/sys/include/net/lwipopts.h
+++ b/src/sys/include/net/lwipopts.h
@@ -47,7 +47,7 @@
 #define LWIP_MPU_COMPATIBLE           0
 #define LWIP_TCPIP_CORE_LOCKING       1
 #define LWIP_TCPIP_CORE_LOCKING_INPUT 0
-#define SYS_LIGHTWEIGHT_PROT          1
+#define SYS_LIGHTWEIGHT_PROT          0
 
 
 #define LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT 0
diff --git a/src/sys/include/net/sys.h b/src/sys/include/net/sys.h
index 622e6af..ada5b1e 100644
--- a/src/sys/include/net/sys.h
+++ b/src/sys/include/net/sys.h
@@ -41,7 +41,7 @@
 
 #if NO_SYS
 
-#else /* NO_SYS */ - Mr O
+#else /* NO_SYS */
 
 /** Return code for timeouts from sys_arch_mbox_fetch and sys_arch_sem_wait */
 #define SYS_ARCH_TIMEOUT 0xffffffffUL
diff --git a/src/sys/net/net/sys_arch.c b/src/sys/net/net/sys_arch.c
index 2caa334..641f2ef 100644
--- a/src/sys/net/net/sys_arch.c
+++ b/src/sys/net/net/sys_arch.c
@@ -22,6 +22,8 @@
 static spinLock_t netThreadSpinlock = SPIN_LOCK_INITIALIZER;
 static struct sys_thread *threads = 0x0;
 
+static uint16_t cond_wait(ubthread_cond_t *cond, ubthread_mutex_t *mutex, uint16_t timeout);
+
 /* sys_arch layer initializer */
 void sys_init() {
   struct timezone tz;
@@ -91,7 +93,7 @@
   kprintf("NEED TO DO THIS");
 }
 
-err_t sys_mutex_new(sys_mutex_t *mutex) {
+err_r sys_mutex_new(sys_mutex_t *mutex) {
   ubthread_mutex_init(&(mutex->mutex), NULL);
   return ERR_OK;
 }
@@ -257,7 +259,6 @@
 }
 
 /* OLD */
-static uint16_t cond_wait(ubthread_cond_t *cond, ubthread_mutex_t *mutex, uint16_t timeout);
 
 struct thread_start_param {
   struct sys_thread *thread;