diff --git a/sys/net/debugnet.c b/sys/net/debugnet.c
--- a/sys/net/debugnet.c
+++ b/sys/net/debugnet.c
@@ -570,10 +570,6 @@
 		    m->m_len, m->m_pkthdr.len);
 		goto done;
 	}
-	if ((m->m_flags & M_HASFCS) != 0) {
-		m_adj(m, -ETHER_CRC_LEN);
-		m->m_flags &= ~M_HASFCS;
-	}
 	eh = mtod(m, struct ether_header *);
 	etype = ntohs(eh->ether_type);
 	if ((m->m_flags & M_VLANTAG) != 0 || etype == ETHERTYPE_VLAN) {
diff --git a/sys/net/ethernet.h b/sys/net/ethernet.h
--- a/sys/net/ethernet.h
+++ b/sys/net/ethernet.h
@@ -40,7 +40,6 @@
 /*
  * Ethernet-specific mbuf flags.
  */
-#define	M_HASFCS	M_PROTO5	/* FCS included at end of frame */
 #define	M_BRIDGE_INJECT	M_PROTO6	/* if_bridge-injected frame */
 
 /*
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -588,16 +588,6 @@
 	 */
 	ETHER_BPF_MTAP(ifp, m);
 
-	/*
-	 * If the CRC is still on the packet, trim it off. We do this once
-	 * and once only in case we are re-entered. Nothing else on the
-	 * Ethernet receive path expects to see the FCS.
-	 */
-	if (m->m_flags & M_HASFCS) {
-		m_adj(m, -ETHER_CRC_LEN);
-		m->m_flags &= ~M_HASFCS;
-	}
-
 	if (!(ifp->if_capenable & IFCAP_HWSTATS))
 		if_inc_counter(ifp, IFCOUNTER_IBYTES, m->m_pkthdr.len);