diff --git a/src/core/memp.c b/src/core/memp.c
index 5d13d4ae..bb34fe76 100644
--- a/src/core/memp.c
+++ b/src/core/memp.c
@@ -120,7 +120,7 @@ static u8_t memp_memory[(MEMP_NUM_PBUF *
 static sys_sem_t mutex;
 #endif
 /*-----------------------------------------------------------------------------------*/
-#ifdef LWIP_DEBUG
+#ifndef LWIP_NOASSERT
 static int
 memp_sanity(void)
 {
diff --git a/src/include/lwip/debug.h b/src/include/lwip/debug.h
index 3e09dfbc..cc9b0c55 100644
--- a/src/include/lwip/debug.h
+++ b/src/include/lwip/debug.h
@@ -61,19 +61,19 @@
 /** flag for LWIP_DEBUGF to halt after printing this debug message */
 #define DBG_HALT    0x08U
 
-#ifdef LWIP_DEBUG
-# ifndef LWIP_NOASSERT
+#ifndef LWIP_NOASSERT
 #  define LWIP_ASSERT(x,y) do { if(!(y)) LWIP_PLATFORM_ASSERT(x); } while(0)
-# else
+#else
 #  define LWIP_ASSERT(x,y) 
-# endif
+#endif
+
+#ifdef LWIP_DEBUG
 /** print debug message only if debug message type is enabled...
  *  AND is of correct type AND is at least DBG_LEVEL
  */
 #  define LWIP_DEBUGF(debug,x) do { if (((debug) & DBG_ON) && ((debug) & DBG_TYPES_ON) && (((debug) & DBG_MASK_LEVEL) >= DBG_MIN_LEVEL)) { LWIP_PLATFORM_DIAG(x); if ((debug) & DBG_HALT) while(1); } } while(0)
 #  define LWIP_ERROR(x)   do { LWIP_PLATFORM_DIAG(x); } while(0)  
 #else /* LWIP_DEBUG */
-#  define LWIP_ASSERT(x,y) 
 #  define LWIP_DEBUGF(debug,x) 
 #  define LWIP_ERROR(x)  
 #endif /* LWIP_DEBUG */
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index b6e70117..237bde45 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -32,9 +32,9 @@
 #ifndef __LWIP_OPT_H__
 #define __LWIP_OPT_H__
 
-#include "lwip/debug.h"
 /* Include user defined options first */
 #include "lwipopts.h"
+#include "lwip/debug.h"
 
 /* Define default values for unconfigured parameters. */