How can I find out what changes the value in /proc/sys/kernel/sysrq?

For some reason the value stored in the /proc/sys/kernel/sysrq file on my system changes to 16. It happens quite frequently, like once-twice an hour but in a random moment of time. As I understand, I can't use inotify, because files under /proc aren't actually files. So how can I find out what changes this value? UPD: Tried to change kernel config in /boot to have

CONFIG_MAGIC_SYSRQ=y
CONFIG_MAGIC_SYSRQ_DEFAULT_ENABLE=0x0001
CONFIG_MAGIC_SYSRQ_SERIAL=y
CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE=""

And also editing /etc/sysct.conf to have

kernel.sysrq=1

And finally just echo 1 > /proc/sys/kernel/sysrq. The last one helps for a bit, but later it drops to 16 again.