diff --git a/monitor/control.c b/monitor/control.c
index 95582a4..ae1a7ae 100644
--- a/monitor/control.c
+++ b/monitor/control.c
@@ -45,10 +45,12 @@
 #include "btsnoop.h"
 #include "control.h"
 
+#define MAX_PACKET_SIZE		(1486 + 4)
+
 struct control_data {
 	uint16_t channel;
 	int fd;
-	unsigned char buf[HCI_MAX_FRAME_SIZE];
+	unsigned char buf[MAX_PACKET_SIZE];
 	uint16_t offset;
 };
 
@@ -772,7 +774,7 @@ void control_server(const char *path)
 
 void control_reader(const char *path)
 {
-	unsigned char buf[HCI_MAX_FRAME_SIZE];
+	unsigned char buf[MAX_PACKET_SIZE];
 	uint16_t index, opcode, pktlen;
 	struct timeval tv;
 
diff --git a/monitor/hcidump.c b/monitor/hcidump.c
index 4eb0a49..e69bcb1 100644
--- a/monitor/hcidump.c
+++ b/monitor/hcidump.c
@@ -108,7 +108,7 @@ static int open_hci_dev(uint16_t index)
 static void device_callback(int fd, uint32_t events, void *user_data)
 {
 	struct hcidump_data *data = user_data;
-	unsigned char buf[HCI_MAX_FRAME_SIZE];
+	unsigned char buf[HCI_MAX_FRAME_SIZE * 2];
 	unsigned char control[64];
 	struct msghdr msg;
 	struct iovec iov;
diff --git a/monitor/packet.c b/monitor/packet.c
index d90dc24..a080ff7 100644
--- a/monitor/packet.c
+++ b/monitor/packet.c
@@ -3833,7 +3833,8 @@ void packet_hci_acldata(struct timeval *tv, uint16_t index, bool in,
 						handle_str, extra_str);
 
 	if (size != dlen) {
-		print_field("invalid packet size");
+		print_field("invalid packet size (%d != %d)", size, dlen);
+		packet_hexdump(data, size);
 		return;
 	}
 
@@ -3883,7 +3884,8 @@ void packet_hci_scodata(struct timeval *tv, uint16_t index, bool in,
 						handle_str, extra_str);
 
 	if (size != hdr->dlen) {
-		print_field("invalid packet size");
+		print_field("invalid packet size (%d != %d)", size, hdr->dlen);
+		packet_hexdump(data, size);
 		return;
 	}