diff --git a/config/boards/shields/lab68/lab68_mcuboot_defconfig b/config/boards/shields/lab68/lab68_mcuboot_defconfig
index 5099297..df47a8a 100644
--- a/config/boards/shields/lab68/lab68_mcuboot_defconfig
+++ b/config/boards/shields/lab68/lab68_mcuboot_defconfig
@@ -43,6 +43,7 @@ CONFIG_USB_DEVICE_VID=0x1FC9
 CONFIG_BOOT_SIGNATURE_TYPE_RSA=n
 CONFIG_BOOT_SIGNATURE_TYPE_ED25519=y
 CONFIG_BOOT_SIGNATURE_KEY_FILE="signing-key-ed25519.pem"
+CONFIG_MCUBOOT_SIGNATURE_KEY_FILE="mcuboot/signing-key-ed25519.pem"
 
 # Maybe in the feature use DFU instead of CDC ACM?
 # CONFIG_BOOT_USB_DFU_NO=n