diff --git a/prj.conf b/prj.conf
index bd66e05..81d31da 100644
--- a/prj.conf
+++ b/prj.conf
@@ -92,6 +92,8 @@ CONFIG_BT_SMP_SC_ONLY=y
 CONFIG_BT_SETTINGS=y
 # Maximum number of stored bonded peers.
 CONFIG_BT_MAX_PAIRED=20
+# Production secure boot: disable flash patching so only signed flash code can run.
+CONFIG_DISABLE_FLASH_PATCH=y
 
 # ADC (battery)
 # Enable Zephyr ADC driver for battery voltage measurement.