diff --git a/bpf_filter.c b/bpf_filter.c
index 1a8ae8c843..ebfd23dd3d 100644
--- a/bpf_filter.c
+++ b/bpf_filter.c
@@ -82,7 +82,8 @@ enum {
  *
  * Thanks to Ani Sinha <ani@arista.com> for providing initial implementation
  */
-#if defined(SKF_AD_VLAN_TAG_PRESENT)
+/* Npcap does not provide auxiliary data */
+#if defined(SKF_AD_VLAN_TAG_PRESENT) && !defined(NPCAP_AD_VLAN_TAG_PRESENT)
 u_int
 pcapint_filter_with_aux_data(const struct bpf_insn *pc, const u_char *p,
     u_int wirelen, u_int buflen, const struct pcap_bpf_aux_data *aux_data)
@@ -142,7 +143,7 @@ pcapint_filter_with_aux_data(const struct bpf_insn *pc, const u_char *p,
 DIAG_OFF_DEFAULT_ONLY_SWITCH
 			switch (pc->k) {
 
-#if defined(SKF_AD_VLAN_TAG_PRESENT)
+#if defined(SKF_AD_VLAN_TAG_PRESENT) && !defined(NPCAP_AD_VLAN_TAG_PRESENT)
 			case SKF_AD_OFF + SKF_AD_VLAN_TAG:
 				if (!aux_data)
 					return 0;
diff --git a/bpf_image.c b/bpf_image.c
index c23d1313a7..17e296999f 100644
--- a/bpf_image.c
+++ b/bpf_image.c
@@ -48,11 +48,18 @@
 #include "os-proto.h"
 #endif
 
-#ifdef SKF_AD_OFF
+#if defined(SKF_AD_OFF) || defined(NPCAP_AD_OFF)
 /*
- * Symbolic names for offsets that refer to the special Linux BPF locations.
+ * Symbolic names for special offsets that refer to platform-specific BPF extensions.
  */
-static const char *offsets[SKF_AD_MAX] = {
+#ifdef NPCAP_AD_MAX
+#define BPFEXT_AD_OFF NPCAP_AD_OFF
+#define BPFEXT_AD_MAX NPCAP_AD_MAX
+#else
+#define BPFEXT_AD_OFF SKF_AD_OFF
+#define BPFEXT_AD_MAX SKF_AD_MAX
+#endif
+static const char *offsets[BPFEXT_AD_MAX] = {
 #ifdef SKF_AD_PROTOCOL
 	[SKF_AD_PROTOCOL] = "proto",
 #endif
@@ -86,10 +93,14 @@ static const char *offsets[SKF_AD_MAX] = {
 #ifdef SKF_AD_ALU_XOR_X
 	[SKF_AD_ALU_XOR_X] = "xor_x",
 #endif
-#ifdef SKF_AD_VLAN_TAG
+#ifdef NPCAP_AD_VLAN_TAG
+	[NPCAP_AD_VLAN_TAG] = "vlan_tci",
+#elif defined(SKF_AD_VLAN_TAG)
 	[SKF_AD_VLAN_TAG] = "vlan_tci",
 #endif
-#ifdef SKF_AD_VLAN_TAG_PRESENT
+#ifdef NPCAP_AD_VLAN_TAG_PRESENT
+	[NPCAP_AD_VLAN_TAG_PRESENT] = "vlanp",
+#elif defined(SKF_AD_VLAN_TAG_PRESENT)
 	[SKF_AD_VLAN_TAG_PRESENT] = "vlanp",
 #endif
 #ifdef SKF_AD_PAY_OFFSET
@@ -107,16 +118,16 @@ static const char *offsets[SKF_AD_MAX] = {
 static void
 bpf_print_abs_load_operand(char *buf, size_t bufsize, const struct bpf_insn *p)
 {
-#ifdef SKF_AD_OFF
+#ifdef BPFEXT_AD_OFF
 	const char *sym;
 
 	/*
 	 * It's an absolute load.
 	 * Is the offset a special Linux offset that we know about?
 	 */
-	if (p->k >= (bpf_u_int32)SKF_AD_OFF &&
-	    p->k < (bpf_u_int32)(SKF_AD_OFF + SKF_AD_MAX) &&
-	    (sym = offsets[p->k - (bpf_u_int32)SKF_AD_OFF]) != NULL) {
+	if (p->k >= (bpf_u_int32)BPFEXT_AD_OFF &&
+	    p->k < (bpf_u_int32)(BPFEXT_AD_OFF + BPFEXT_AD_MAX) &&
+	    (sym = offsets[p->k - (bpf_u_int32)BPFEXT_AD_OFF]) != NULL) {
 		/*
 		 * Yes.  Print the offset symbolically.
 		 */
diff --git a/gencode.c b/gencode.c
index b2e092f475..ab5b96f419 100644
--- a/gencode.c
+++ b/gencode.c
@@ -9222,6 +9222,13 @@ gen_vlan_no_bpf_extensions(compiler_state_t *cstate, bpf_u_int32 vlan_num,
 	return b0;
 }
 
+/* Npcap defines these constants in a way that is compatible with Linux, as
+ * long as no assumptions are made about the value or ordering. */
+#if defined(NPCAP_AD_OFF) && !defined(SKF_AD_OFF)
+#define SKF_AD_OFF              NPCAP_AD_OFF
+#define SKF_AD_VLAN_TAG         NPCAP_AD_VLAN_TAG
+#define SKF_AD_VLAN_TAG_PRESENT NPCAP_AD_VLAN_TAG_PRESENT
+#endif
 #if defined(SKF_AD_VLAN_TAG_PRESENT)
 /* add v to variable part of off */
 static void
@@ -9418,7 +9425,7 @@ gen_vlan(compiler_state_t *cstate, bpf_u_int32 vlan_num, int has_vlan_tag)
 		 *
 		 * This requires special treatment.
 		 */
-#if defined(SKF_AD_VLAN_TAG_PRESENT)
+#if defined(SKF_AD_VLAN_TAG_PRESENT) || defined(NPCAP_AD_VLAN_TAG_PRESENT)
 		/* Verify that this is the outer part of the packet and
 		 * not encapsulated somehow. */
 		if (cstate->vlan_stack_depth == 0 && !cstate->off_linkhdr.is_variable &&
diff --git a/pcap-npf.c b/pcap-npf.c
index 4feee30cfd..dc7d03e5d4 100644
--- a/pcap-npf.c
+++ b/pcap-npf.c
@@ -1090,13 +1090,18 @@ pcap_activate_npf(pcap_t *p)
 	}
 #endif /* HAVE_PACKET_GET_TIMESTAMP_MODES */
 
-#if defined(HAVE_PACKET_GET_INFO) && defined(NPF_GETINFO_BPFEXT) && defined(SKF_AD_VLAN_TAG_PRESENT)
+/* Npcap SDK 1.15 defined SKF_AD_* constants; later versions prefer NPCAP_AD_* */
+#if !defined(NPCAP_AD_VLAN_TAG_PRESENT) && defined(SKF_AD_VLAN_TAG_PRESENT)
+#define NPCAP_AD_VLAN_TAG_PRESENT SKF_AD_VLAN_TAG_PRESENT
+#endif
+
+#if defined(HAVE_PACKET_GET_INFO) && defined(NPF_GETINFO_BPFEXT) && defined(NPCAP_AD_VLAN_TAG_PRESENT)
 
 	/* Can we generate special code for VLAN checks? */
 	oid_data_arg->Oid = NPF_GETINFO_BPFEXT;
 	oid_data_arg->Length = sizeof(ULONG);
 	if (PacketGetInfo(pw->adapter, oid_data_arg)) {
-		if (*((ULONG *)oid_data_arg->Data) >= SKF_AD_VLAN_TAG_PRESENT) {
+		if (*((ULONG *)oid_data_arg->Data) >= NPCAP_AD_VLAN_TAG_PRESENT) {
 			/* Yes, we can.  Request that we do so. */
 			p->bpf_codegen_flags |= BPF_SPECIAL_VLAN_HANDLING;
 		}