diff --git a/sys/conf/files.riscv b/sys/conf/files.riscv
index 774dabe0cd61..192a309c989e 100644
--- a/sys/conf/files.riscv
+++ b/sys/conf/files.riscv
@@ -1,6 +1,7 @@
 # $FreeBSD$
 cddl/dev/dtrace/riscv/dtrace_asm.S			optional dtrace compile-with "${DTRACE_S}"
 cddl/dev/dtrace/riscv/dtrace_subr.c			optional dtrace compile-with "${DTRACE_C}"
+cddl/dev/dtrace/riscv/instr_size.c			optional dtrace compile-with "${DTRACE_C}"
 cddl/dev/fbt/riscv/fbt_isa.c				optional dtrace_fbt | dtraceall compile-with "${FBT_C}"
 crypto/des/des_enc.c		optional	netsmb
 dev/ofw/ofw_cpu.c		optional	fdt