diff --git a/boot/zephyr/prj.conf b/boot/zephyr/prj.conf
index 60fd5e8..aec69e8 100644
--- a/boot/zephyr/prj.conf
+++ b/boot/zephyr/prj.conf
@@ -32,6 +32,7 @@
 
 CONFIG_MULTITHREADING=n
 
-### Zephyr keeps turning on major subsystems by default that we don't want.
+### Various Zephyr boards enable features that we don't want.
 # CONFIG_BT is not set
+# CONFIG_BT_CTLR is not set
 # CONFIG_I2C is not set