1 files changed, 7 insertions, 0 deletions
diff --git a/src/class/bth/bth_device.h b/src/class/bth/bth_device.h
index 921bd7a1a..e782c532b 100755
--- a/src/class/bth/bth_device.h
+++ b/src/class/bth/bth_device.h
@@ -36,10 +36,17 @@
 #ifndef CFG_TUD_BTH_EVENT_EPSIZE
 #define CFG_TUD_BTH_EVENT_EPSIZE     16
 #endif
+
 #ifndef CFG_TUD_BTH_DATA_EPSIZE
 #define CFG_TUD_BTH_DATA_EPSIZE      64
 #endif
 
+// Allow BTH class to work in historically compatibility mode where the bRequest is always 0xe0.
+// See Bluetooth Core v5.3, Vol. 4, Part B, Section 2.2
+#ifndef CFG_TUD_BTH_HISTORICAL_COMPATIBLE
+#define CFG_TUD_BTH_HISTORICAL_COMPATIBLE 0
+#endif
+
 typedef struct TU_ATTR_PACKED
 {
   uint16_t op_code;