diff --git a/src/include/lwip/memp.h b/src/include/lwip/memp.h
index 0b6fe043..bb45f6c4 100644
--- a/src/include/lwip/memp.h
+++ b/src/include/lwip/memp.h
@@ -91,7 +91,7 @@ extern const struct memp_desc* const memp_pools[MEMP_MAX];
 #else /* MEMP_MEM_MALLOC */
 
 #define LWIP_MEMPOOL_DECLARE(name,num,size,desc) u8_t memp_memory_ ## name ## _base \
-    [((num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size)))]; \
+    [LWIP_MEM_ALIGN_SIZE(((num) * (MEMP_SIZE + MEMP_ALIGN_SIZE(size))))]; \
     \
   static struct memp *memp_tab_ ## name; \
     \