diff --git a/src/core/ipv4/ip.c b/src/core/ipv4/ip.c
index ad76c763..dabced12 100644
--- a/src/core/ipv4/ip.c
+++ b/src/core/ipv4/ip.c
@@ -350,8 +350,8 @@ ip_input(struct pbuf *p, struct netif *inp) {
 
 #if IP_REASSEMBLY
   if ((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0) {
-    LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04x tot_len=%u len=%u MF=%u offset=%u),
-      calling ip_reass()\n", ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & htons(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
+    LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04x tot_len=%u len=%u MF=%u offset=%u), calling ip_reass()\n",
+      ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & htons(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
     p = ip_reass(p);
     if (p == NULL) {
       return ERR_OK;
diff --git a/src/core/mem.c b/src/core/mem.c
index ff477144..3a8a3f54 100644
--- a/src/core/mem.c
+++ b/src/core/mem.c
@@ -63,11 +63,13 @@ static struct mem *ram_end;
 static u8_t ram[MEM_SIZE + sizeof(struct mem) + MEM_ALIGNMENT];
 
 #define MIN_SIZE 12
-#define SIZEOF_STRUCT_MEM MEM_ALIGN_SIZE(sizeof(struct mem))
-/*#define SIZEOF_STRUCT_MEM (sizeof(struct mem) + \
+#if 0 /* this one does not align correctly for some, resulting in crashes */
+#define SIZEOF_STRUCT_MEM (unsigned int)MEM_ALIGN_SIZE(sizeof(struct mem))
+#else
+#define SIZEOF_STRUCT_MEM (sizeof(struct mem) + \
                           (((sizeof(struct mem) % MEM_ALIGNMENT) == 0)? 0 : \
-                          (4 - (sizeof(struct mem) % MEM_ALIGNMENT))))*/
-
+                          (4 - (sizeof(struct mem) % MEM_ALIGNMENT))))
+#endif
 
 static struct mem *lfree;   /* pointer to the lowest free block */