diff --git a/lib/ff_veth.c b/lib/ff_veth.c
index 778dd4997..3e70ac83e 100644
--- a/lib/ff_veth.c
+++ b/lib/ff_veth.c
@@ -448,8 +448,9 @@ void * ff_mbuf_mtod(void* bsd_mbuf)
 void* ff_rte_frm_extcl(void* mbuf)
 {
     struct mbuf *bsd_mbuf = mbuf;
-    
-    if ( bsd_mbuf->m_ext.ext_type==EXT_DISPOSABLE && bsd_mbuf->m_ext.ext_free==ff_mbuf_ext_free ){
+
+    if ( (bsd_mbuf->m_flags & M_EXT) &&
+        bsd_mbuf->m_ext.ext_type == EXT_DISPOSABLE && bsd_mbuf->m_ext.ext_free == ff_mbuf_ext_free ) {
         return bsd_mbuf->m_ext.ext_arg1;
     }
     else