diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c
index 2b6d39fd82..ff88980f5f 100644
--- a/common/usb_pd_protocol.c
+++ b/common/usb_pd_protocol.c
@@ -234,7 +234,8 @@ static inline int pd_is_vbus_present(int port)
 
 static int pd_snk_debug_acc_toggle(int port)
 {
-#ifdef CONFIG_CASE_CLOSED_DEBUG
+#if defined(CONFIG_CASE_CLOSED_DEBUG) || \
+defined(CONFIG_CASE_CLOSED_DEBUG_EXTERNAL)
 	/*
 	 * when we are in SNK_DISCONNECTED and we see VBUS appearing
 	 * (without having seen Rp before), that might be a powered debug
@@ -249,7 +250,8 @@ static int pd_snk_debug_acc_toggle(int port)
 
 static int pd_debug_acc_plugged(int port)
 {
-#ifdef CONFIG_CASE_CLOSED_DEBUG
+#if defined(CONFIG_CASE_CLOSED_DEBUG) || \
+defined(CONFIG_CASE_CLOSED_DEBUG_EXTERNAL)
 	return pd[port].task_state == PD_STATE_SRC_ACCESSORY;
 #else
 	/* Debug accessories not supported */
diff --git a/include/config.h b/include/config.h
index d868d5671e..d3b15932cf 100644
--- a/include/config.h
+++ b/include/config.h
@@ -312,9 +312,11 @@
 #undef CONFIG_BUTTON_COUNT
 
 /*
- * Enable case close debug (CCD) mode.
+ * Enable case close debug (CCD) mode in the EC.
  */
 #undef CONFIG_CASE_CLOSED_DEBUG
+/* The case close debug (CCD) feature is provided by an external chip. */
+#undef CONFIG_CASE_CLOSED_DEBUG_EXTERNAL
 
 /*
  * Capsense chip has buttons, too.