diff --git a/arch/s390/defconfig b/arch/s390/defconfig
index 29c82c6..6cf8e26 100644
--- a/arch/s390/defconfig
+++ b/arch/s390/defconfig
@@ -68,7 +68,7 @@
 CONFIG_NET_CLS_ACT=y
 CONFIG_NET_ACT_POLICE=y
 CONFIG_UEVENT_HELPER_PATH="/sbin/hotplug"
-# CONFIG_FIRMWARE_IN_KERNEL is not set
+CONFIG_DEVTMPFS=y
 CONFIG_BLK_DEV_LOOP=m
 CONFIG_BLK_DEV_NBD=m
 CONFIG_BLK_DEV_RAM=y