diff --git a/cores/esp32/esp32-hal-bt.c b/cores/esp32/esp32-hal-bt.c
index d17a761bebd..7b6a54e1ad4 100644
--- a/cores/esp32/esp32-hal-bt.c
+++ b/cores/esp32/esp32-hal-bt.c
@@ -16,7 +16,8 @@
 
 #ifdef CONFIG_BT_ENABLED
 
-bool btInUse(){ return true; }
+// user may want to change it to free resources
+__attribute__((weak)) bool btInUse(){ return true; }
 
 #include "esp_bt.h"
 
diff --git a/cores/esp32/esp32-hal-misc.c b/cores/esp32/esp32-hal-misc.c
index 1a71b0e86f9..9bc1b3a3a8e 100644
--- a/cores/esp32/esp32-hal-misc.c
+++ b/cores/esp32/esp32-hal-misc.c
@@ -209,9 +209,8 @@ bool verifyRollbackLater() { return false; }
 #endif
 
 #ifdef CONFIG_BT_ENABLED
-//overwritten in esp32-hal-bt.c
-bool btInUse() __attribute__((weak));
-bool btInUse(){ return false; }
+//from esp32-hal-bt.c
+extern bool btInUse();
 #endif
 
 void initArduino()