diff --git a/bpf_image.c b/bpf_image.c
index 3e9a23f..0b9e0b9 100644
--- a/bpf_image.c
+++ b/bpf_image.c
@@ -305,6 +305,17 @@ bpf_image(p, n)
 		op = "txa";
 		fmt = "";
 		break;
+
+	case BPF_MISC|BPF_COP:
+		op = "cop";
+		fmt = "#%d";
+		break;
+
+	case BPF_MISC|BPF_COPX:
+		op = "copx";
+		fmt = "x";
+		break;
+
 	}
 	(void)snprintf(operand, sizeof operand, fmt, v);
 	if (BPF_CLASS(p->code) == BPF_JMP && BPF_OP(p->code) != BPF_JA) {
diff --git a/gencode.c b/gencode.c
index aefd38b..ef343cb 100644
--- a/gencode.c
+++ b/gencode.c
@@ -7333,6 +7333,26 @@ gen_byteop(op, idx, val)
 	return b;
 }
 
+struct block *
+gen_cop(accum, idx, ret)
+	int accum, idx, ret;
+{
+	struct slist *s1, *s2;
+	struct block *b;
+
+	s1 = new_stmt(BPF_LD|BPF_IMM);
+	s1->s.k = accum;
+
+	s2 = new_stmt(BPF_MISC|BPF_COP);
+	s2->s.k = idx;
+	sappend(s1, s2);
+
+	b = new_block(JMP(BPF_JEQ));
+	b->stmts = s1;
+	b->s.k = ret;
+	return b;
+}
+
 static u_char abroadcast[] = { 0x0 };
 
 struct block *
diff --git a/gencode.h b/gencode.h
index e6b3a71..9e1132d 100644
--- a/gencode.h
+++ b/gencode.h
@@ -304,6 +304,7 @@ struct block *gen_relation(int, struct arth *, struct arth *, int);
 struct block *gen_less(int);
 struct block *gen_greater(int);
 struct block *gen_byteop(int, int, int);
+struct block *gen_cop(int, int, int);
 struct block *gen_broadcast(int);
 struct block *gen_multicast(int);
 struct block *gen_inbound(int);
diff --git a/grammar.y b/grammar.y
index b269d27..27af6ce 100644
--- a/grammar.y
+++ b/grammar.y
@@ -310,6 +310,7 @@ pfaction_to_num(const char *action)
 %token	RADIO
 %token	FISU LSSU MSU HFISU HLSSU HMSU
 %token	SIO OPC DPC SLS HSIO HOPC HDPC HSLS
+%token	COP
  
 
 %type	<s> ID
@@ -514,6 +515,7 @@ other:	  pqual TK_BROADCAST	{ $$ = gen_broadcast($1); }
 	| LESS NUM		{ $$ = gen_less($2); }
 	| GREATER NUM		{ $$ = gen_greater($2); }
 	| CBYTE NUM byteop NUM	{ $$ = gen_byteop($3, $2, $4); }
+	| COP NUM NUM NUM	{ $$ = gen_cop($2, $3, $4); }
 	| INBOUND		{ $$ = gen_inbound(0); }
 	| OUTBOUND		{ $$ = gen_inbound(1); }
 	| VLAN pnum		{ $$ = gen_vlan($2); }
diff --git a/optimize.c b/optimize.c
index feaf201..8f29990 100644
--- a/optimize.c
+++ b/optimize.c
@@ -1089,6 +1089,11 @@ opt_stmt(struct stmt *s, int val[], int alter)
 		vstore(s, &val[X_ATOM], val[A_ATOM], alter);
 		break;
 
+	case BPF_MISC|BPF_COP:
+		v = F(s->code, 0L, 0L);
+		vstore(s, &val[A_ATOM], v, alter);
+		break;
+
 	case BPF_LDX|BPF_MEM:
 		v = val[s->k];
 		if (alter && vmap[v].is_const) {
diff --git a/pcap-filter.manmisc.in b/pcap-filter.manmisc.in
index f65a6a9..bdb255b 100644
--- a/pcap-filter.manmisc.in
+++ b/pcap-filter.manmisc.in
@@ -18,7 +18,7 @@
 .\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 .\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 .\"
-.TH PCAP-FILTER @MAN_MISC_INFO@ "17 May 2013"
+.TH PCAP-FILTER @MAN_MISC_INFO@ "29 January 2015"
 .SH NAME
 pcap-filter \- packet filter syntax
 .br
@@ -796,6 +796,17 @@ Connect Ack, Release, or Release Done message.
 True if the packet is an ATM packet, for SunATM on Solaris, and is
 on a meta signaling circuit and is a Q.2931 Setup, Call Proceeding, Connect,
 Release, or Release Done message.
+.IP "\fBcop \fIaccum \fIindex \fIretval\fR"
+Sets the accumulator register to
+.IR accum
+and invokes the BPF coprocessor function given the
+.IR index .
+True if the value returned by the function matches
+.IR retval .
+If the coprocessor is not set or the function index is out of range,
+then the program will be aborted.
+This keyword is applicable only for the custom BPF interpreters which
+have the coprocessor support.
 .IP  "\fIexpr relop expr\fR"
 True if the relation holds, where \fIrelop\fR is one of >, <, >=, <=, =,
 !=, and \fIexpr\fR is an arithmetic expression composed of integer
diff --git a/pcap-int.h b/pcap-int.h
index 2f71e11..470caf9 100644
--- a/pcap-int.h
+++ b/pcap-int.h
@@ -340,6 +340,16 @@ struct oneshot_userdata {
 
 int	yylex(void);
 
+/*
+ * NOTE: NetBSD - TBD on exposing
+ */
+#ifndef BPF_COP
+#define	BPF_COP		0x20
+#endif
+#ifndef BPF_COPX
+#define	BPF_COPX	0x40
+#endif
+
 #ifndef min
 #define min(a, b) ((a) > (b) ? (b) : (a))
 #endif
diff --git a/scanner.l b/scanner.l
index a247c99..1083cba 100644
--- a/scanner.l
+++ b/scanner.l
@@ -295,6 +295,8 @@ vci		return VCI;
 connectmsg	return CONNECTMSG;
 metaconnect	return METACONNECT;
 
+cop		return COP;
+
 on|ifname	return PF_IFNAME;
 rset|ruleset	return PF_RSET;
 rnr|rulenum	return PF_RNR;