diff --git a/firmware/2lib/2ui_screens.c b/firmware/2lib/2ui_screens.c
index 2510392..04f037b 100644
--- a/firmware/2lib/2ui_screens.c
+++ b/firmware/2lib/2ui_screens.c
@@ -433,6 +433,13 @@
 	if (!ui->key_trusted) {
 		VB2_DEBUG("Reject untrusted %s confirmation\n",
 			  ui->key == VB_KEY_ENTER ? "ENTER" : "POWER");
+		/*
+		 * If physical presence is confirmed using the keyboard,
+		 * beep and notify the user when the ENTER key comes
+		 * from an untrusted keyboard.
+		 */
+		if (PHYSICAL_PRESENCE_KEYBOARD && ui->key == VB_KEY_ENTER)
+			ui->error_code = VB2_UI_ERROR_UNTRUSTED_CONFIRMATION;
 		return VB2_REQUEST_UI_CONTINUE;
 	}
 	return recovery_to_dev_finalize(ui);
diff --git a/firmware/2lib/include/2api.h b/firmware/2lib/include/2api.h
index 205b289..c6d99bd 100644
--- a/firmware/2lib/include/2api.h
+++ b/firmware/2lib/include/2api.h
@@ -1309,6 +1309,8 @@
 	VB2_UI_ERROR_DEV_MODE_ALREADY_ENABLED,
 	/* Debug info screen initialization failed */
 	VB2_UI_ERROR_DEBUG_LOG,
+	/* Untrusted confirmation */
+	VB2_UI_ERROR_UNTRUSTED_CONFIRMATION,
 };
 
 /**