diff --git a/usr.bin/truss/syscalls.c b/usr.bin/truss/syscalls.c
index 46077fddf5dc..3c8418c4811f 100644
--- a/usr.bin/truss/syscalls.c
+++ b/usr.bin/truss/syscalls.c
@@ -231,6 +231,8 @@ static struct syscall decoded_syscalls[] = {
 		    { Atflags, 4 } } },
 	{ .name = "fcntl", .ret_type = 1, .nargs = 3,
 	  .args = { { Int, 0 }, { Fcntl, 1 }, { Fcntlflag, 2 } } },
+	{ .name = "fdatasync", .ret_type = 1, .nargs = 1,
+	  .args = { { Int, 0 } } },
 	{ .name = "flock", .ret_type = 1, .nargs = 2,
 	  .args = { { Int, 0 }, { Flockop, 1 } } },
 	{ .name = "fstat", .ret_type = 1, .nargs = 2,
@@ -240,6 +242,8 @@ static struct syscall decoded_syscalls[] = {
 		    { Atflags, 3 } } },
 	{ .name = "fstatfs", .ret_type = 1, .nargs = 2,
 	  .args = { { Int, 0 }, { StatFs | OUT, 1 } } },
+	{ .name = "fsync", .ret_type = 1, .nargs = 1,
+	  .args = { { Int, 0 } } },
 	{ .name = "ftruncate", .ret_type = 1, .nargs = 2,
 	  .args = { { Int | IN, 0 }, { QuadHex | IN, 1 } } },
 	{ .name = "futimens", .ret_type = 1, .nargs = 2,