diff --git a/wlantest/readpcap.c b/wlantest/readpcap.c
index 7c3ce18fd..6c3853b05 100644
--- a/wlantest/readpcap.c
+++ b/wlantest/readpcap.c
@@ -102,6 +102,8 @@ int read_cap_file(struct wlantest *wt, const char *fname)
 				write_pcap_with_radiotap(wt, data, hdr->caplen);
 			else
 				pcap_dump(wt->write_pcap_dumper, hdr, data);
+			if (wt->pcap_no_buffer)
+				pcap_dump_flush(wt->write_pcap_dumper);
 		}
 		if (hdr->caplen < hdr->len) {
 			add_note(wt, MSG_DEBUG, "pcap: Dropped incomplete "
diff --git a/wlantest/wlantest.c b/wlantest/wlantest.c
index ab3b2fc6b..abe97d18f 100644
--- a/wlantest/wlantest.c
+++ b/wlantest/wlantest.c
@@ -21,7 +21,7 @@ static void wlantest_terminate(int sig, void *signal_ctx)
 
 static void usage(void)
 {
-	printf("wlantest [-cddhqqFt] [-i<ifname>] [-r<pcap file>] "
+	printf("wlantest [-cddhqqFNt] [-i<ifname>] [-r<pcap file>] "
 	       "[-p<passphrase>]\n"
 	       "         [-I<wired ifname>] [-R<wired pcap file>] "
 	       "[-P<RADIUS shared secret>]\n"
@@ -350,7 +350,7 @@ int main(int argc, char *argv[])
 	wlantest_init(&wt);
 
 	for (;;) {
-		c = getopt(argc, argv, "cdf:Fhi:I:L:n:p:P:qr:R:tT:w:W:");
+		c = getopt(argc, argv, "cdf:Fhi:I:L:n:Np:P:qr:R:tT:w:W:");
 		if (c < 0)
 			break;
 		switch (c) {
@@ -383,6 +383,9 @@ int main(int argc, char *argv[])
 		case 'n':
 			wt.pcapng_file = optarg;
 			break;
+		case 'N':
+			wt.pcap_no_buffer = 1;
+			break;
 		case 'p':
 			add_passphrase(&wt, optarg);
 			break;
diff --git a/wlantest/wlantest.h b/wlantest/wlantest.h
index ced9baa0e..530accc3b 100644
--- a/wlantest/wlantest.h
+++ b/wlantest/wlantest.h
@@ -202,6 +202,7 @@ struct wlantest {
 	int last_mgmt_valid;
 
 	unsigned int assume_fcs:1;
+	unsigned int pcap_no_buffer:1;
 
 	char *notes[MAX_NOTES];
 	size_t num_notes;
diff --git a/wlantest/writepcap.c b/wlantest/writepcap.c
index 28b306b7a..abd889fcd 100644
--- a/wlantest/writepcap.c
+++ b/wlantest/writepcap.c
@@ -59,6 +59,8 @@ void write_pcap_captured(struct wlantest *wt, const u8 *buf, size_t len)
 	h.caplen = len;
 	h.len = len;
 	pcap_dump(wt->write_pcap_dumper, &h, buf);
+	if (wt->pcap_no_buffer)
+		pcap_dump_flush(wt->write_pcap_dumper);
 }
 
 
@@ -102,6 +104,8 @@ void write_pcap_decrypted(struct wlantest *wt, const u8 *buf1, size_t len1,
 	h.caplen = len;
 	h.len = len;
 	pcap_dump(wt->write_pcap_dumper, &h, buf);
+	if (wt->pcap_no_buffer)
+		pcap_dump_flush(wt->write_pcap_dumper);
 }
 
 
@@ -181,6 +185,8 @@ int write_pcapng_init(struct wlantest *wt, const char *fname)
 	desc.link_type = LINKTYPE_IEEE802_11_RADIO;
 	desc.snap_len = 65535;
 	fwrite(&desc, sizeof(desc), 1, wt->pcapng);
+	if (wt->pcap_no_buffer)
+		fflush(wt->pcapng);
 
 	return 0;
 }
@@ -263,6 +269,8 @@ static void write_pcapng_decrypted(struct wlantest *wt)
 	*block_len = pkt->block_total_len = pos - (u8 *) pkt;
 
 	fwrite(pkt, pos - (u8 *) pkt, 1, wt->pcapng);
+	if (wt->pcap_no_buffer)
+		fflush(wt->pcapng);
 
 	os_free(pkt);
 }
@@ -337,6 +345,8 @@ void write_pcapng_write_read(struct wlantest *wt, int dlt,
 	*block_len = pkt->block_total_len = pos - (u8 *) pkt;
 
 	fwrite(pkt, pos - (u8 *) pkt, 1, wt->pcapng);
+	if (wt->pcap_no_buffer)
+		fflush(wt->pcapng);
 
 	os_free(pkt);