diff --git a/pkg/lwip/include/arch/cc.h b/pkg/lwip/include/arch/cc.h
index 2d917fac67..fe058e4d60 100644
--- a/pkg/lwip/include/arch/cc.h
+++ b/pkg/lwip/include/arch/cc.h
@@ -76,10 +76,6 @@ extern "C" {
  * @}
  */
 
-/**
- * @todo check for best value
- */
-#define LWIP_CHKSUM_ALGORITHM   (3)
 
 #ifdef MODULE_LOG
 #  define LWIP_PLATFORM_DIAG(x)   LOG_INFO x
diff --git a/pkg/lwip/include/arch/sys_arch.h b/pkg/lwip/include/arch/sys_arch.h
index ed4fd467af..da9281882e 100644
--- a/pkg/lwip/include/arch/sys_arch.h
+++ b/pkg/lwip/include/arch/sys_arch.h
@@ -35,7 +35,6 @@ extern "C" {
 #endif
 
 #define LWIP_COMPAT_MUTEX   (0)
-#define SYS_SEM_NULL        { 0, PRIORITY_QUEUE_INIT }
 #define SYS_MBOX_SIZE       (8)
 
 typedef struct {