diff --git a/usr.bin/truss/syscalls.c b/usr.bin/truss/syscalls.c
index 306a900aea1e..f12ac46fb990 100644
--- a/usr.bin/truss/syscalls.c
+++ b/usr.bin/truss/syscalls.c
@@ -483,6 +483,8 @@ static struct syscall decoded_syscalls[] = {
 	  .args = { { Long, 0 }, { Signal, 1 } } },
 	{ .name = "thr_self", .ret_type = 1, .nargs = 1,
 	  .args = { { Ptr, 0 } } },
+	{ .name = "thr_set_name", .ret_type = 1, .nargs = 2,
+	  .args = { { Long, 0 }, { Name, 1 } } },
 	{ .name = "truncate", .ret_type = 1, .nargs = 2,
 	  .args = { { Name | IN, 0 }, { QuadHex | IN, 1 } } },
 #if 0