diff --git a/sys/cddl/dev/dtrace/riscv/dtrace_subr.c b/sys/cddl/dev/dtrace/riscv/dtrace_subr.c
index c1ac339b3a2..964be957109 100644
--- a/sys/cddl/dev/dtrace/riscv/dtrace_subr.c
+++ b/sys/cddl/dev/dtrace/riscv/dtrace_subr.c
@@ -162,7 +162,7 @@ dtrace_sync(void)
  * Returns nanoseconds since boot.
  */
 uint64_t
-dtrace_gethrtime()
+dtrace_gethrtime(void)
 {
 	struct timespec curtime;