diff --git a/net/ipfrag/ipv4_frag.c b/net/ipfrag/ipv4_frag.c
index 66091c5c8cf..b3f82329136 100644
--- a/net/ipfrag/ipv4_frag.c
+++ b/net/ipfrag/ipv4_frag.c
@@ -361,7 +361,7 @@ int32_t ipv4_fragout(FAR struct net_driver_s *dev, uint16_t mtu)
   uint32_t nfrags;
   uint16_t offset = 0;
   uint16_t hdrlen;
-  FAR struct iob_s *frag;
+  FAR struct iob_s *frag = NULL;
   FAR struct ipv4_hdr_s *ref = NULL;
   struct iob_queue_s fragq =
     {
@@ -379,9 +379,15 @@ int32_t ipv4_fragout(FAR struct net_driver_s *dev, uint16_t mtu)
    */
 
   nfrags = ip_fragout_slice(dev->d_iob, PF_INET, mtu, hdrlen, &fragq);
-  ASSERT(nfrags > 1);
   netdev_iob_clear(dev);
 
+  /* No I/O Buffer is the only cause of failure */
+
+  if (nfrags == 0)
+    {
+      goto fail;
+    }
+
   /* Fill the L3 header into the reserved space */
 
   for (iter = 0; iter < nfrags; iter++)
diff --git a/net/ipfrag/ipv6_frag.c b/net/ipfrag/ipv6_frag.c
index 3fdb4c845bb..69b09580d69 100644
--- a/net/ipfrag/ipv6_frag.c
+++ b/net/ipfrag/ipv6_frag.c
@@ -570,7 +570,7 @@ int32_t ipv6_fragout(FAR struct net_driver_s *dev, uint16_t mtu)
   uint32_t nfrags;
   uint16_t hdroff;
   uint16_t hdrtype;
-  FAR struct iob_s *frag;
+  FAR struct iob_s *frag = NULL;
   FAR struct ipv6_hdr_s *ref = NULL;
   FAR struct ipv6_fragment_extension_s *fraghdr;
   struct iob_queue_s fragq =
@@ -590,9 +590,15 @@ int32_t ipv6_fragout(FAR struct net_driver_s *dev, uint16_t mtu)
    */
 
   nfrags = ip_fragout_slice(dev->d_iob, PF_INET6, mtu, unfraglen, &fragq);
-  ASSERT(nfrags > 1);
   netdev_iob_clear(dev);
 
+  /* No I/O Buffer is the only cause of failure */
+
+  if (nfrags == 0)
+    {
+      goto fail;
+    }
+
   ipid = ++g_ipv6id;
 
   /* Fill the L3 header into the reserved space */