diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c
--- a/sys/net/if_epair.c
+++ b/sys/net/if_epair.c
@@ -140,6 +140,11 @@
 		m->m_pkthdr.csum_flags &= ~CSUM_SND_TAG;
 	}
 
+	/* Clear vlan information. */
+	m->m_flags &= ~M_VLANTAG;
+	if (m->m_flags & M_PKTHDR)
+		m->m_pkthdr.ether_vtag = 0;
+
 	m_tag_delete_nonpersistent(m);
 }