diff --git a/src/xrt/drivers/wmr/wmr_hmd.c b/src/xrt/drivers/wmr/wmr_hmd.c
index 8d018acf2..1d0a9b4db 100644
--- a/src/xrt/drivers/wmr/wmr_hmd.c
+++ b/src/xrt/drivers/wmr/wmr_hmd.c
@@ -78,6 +78,33 @@ hololens_unknown_17_decode_packet(struct wmr_hmd *wh, const unsigned char *buffe
 static void
 hololens_handle_bt_iface_packet(struct wmr_hmd *wh, const unsigned char *buffer, int size)
 {
+	int pkt_type;
+
+	if (size < 2)
+		return;
+
+	if (size < 6) {
+		WMR_DEBUG(wh, "Short Bluetooth interface packet (%d) type 0x%02x", size, buffer[1]);
+		return;
+	}
+
+	pkt_type = buffer[1];
+	if (pkt_type != WMR_BT_IFACE_MSG_DEBUG) {
+		WMR_DEBUG(wh, "Unknown Bluetooth interface packet (%d) type 0x%02x", size, pkt_type);
+		return;
+	}
+	buffer += 2;
+
+	uint16_t tag = read16(&buffer);
+	uint16_t msg_len = read16(&buffer);
+
+	if (size < msg_len + 6) {
+		WMR_DEBUG(wh, "Bluetooth interface debug packet (%d) too short. tag 0x%x msg len %u", size, tag,
+		          msg_len);
+		return;
+	}
+
+	WMR_DEBUG(wh, "BT debug: tag %d: %.*s", tag, msg_len, buffer);
 }
 
 static void
diff --git a/src/xrt/drivers/wmr/wmr_protocol.h b/src/xrt/drivers/wmr/wmr_protocol.h
index 8de3902e0..4db34fab1 100644
--- a/src/xrt/drivers/wmr/wmr_protocol.h
+++ b/src/xrt/drivers/wmr/wmr_protocol.h
@@ -34,8 +34,8 @@ extern "C" {
 #define WMR_MS_HOLOLENS_MSG_SENSORS 0x01
 #define WMR_MS_HOLOLENS_MSG_CONTROL 0x02 // Integrated motion controller messages?
 #define WMR_MS_HOLOLENS_MSG_DEBUG 0x03
-#define WMR_MS_HOLOLENS_MSG_BT_IFACE 0x05 /* Bluetooth interface */
-#define WMR_MS_HOLOLENS_MSG_LEFT_CONTROLLER 0x06 /* Left controller */
+#define WMR_MS_HOLOLENS_MSG_BT_IFACE 0x05         /* Bluetooth interface */
+#define WMR_MS_HOLOLENS_MSG_LEFT_CONTROLLER 0x06  /* Left controller */
 #define WMR_MS_HOLOLENS_MSG_RIGHT_CONTROLLER 0x0E /* Right controller */
 #define WMR_MS_HOLOLENS_MSG_UNKNOWN_17 0x17
 
@@ -43,6 +43,8 @@ extern "C" {
 #define WMR_CONTROL_MSG_IPD_VALUE 0x01
 #define WMR_CONTROL_MSG_UNKNOWN_05 0x05
 
+#define WMR_BT_IFACE_MSG_DEBUG 0x19
+
 #define STR_TO_U32(s) ((uint32_t)(((s)[0]) | ((s)[1] << 8) | ((s)[2] << 16) | ((s)[3] << 24)))
 #define WMR_MAGIC STR_TO_U32("Dlo+")