diff --git a/dsp/benches/micro.rs b/dsp/benches/micro.rs
index c3588df..a449339 100644
--- a/dsp/benches/micro.rs
+++ b/dsp/benches/micro.rs
@@ -44,11 +44,11 @@ fn pll_bench() {
     let mut dut = PLL::default();
     println!(
         "PLL::update(t, 12, 12): {}",
-        bench_env(0x241, |x| dut.update(*x, 12, 12))
+        bench_env(Some(0x241), |x| dut.update(*x, 12, 12))
     );
     println!(
         "PLL::update(t, sf, sp): {}",
-        bench_env((0x241, 21, 20), |(x, p, q)| dut.update(*x, *p, *q))
+        bench_env((Some(0x241), 21, 20), |(x, p, q)| dut.update(*x, *p, *q))
     );
 }
 
diff --git a/dsp/src/pll.rs b/dsp/src/pll.rs
index 09a5464..1c6a782 100644
--- a/dsp/src/pll.rs
+++ b/dsp/src/pll.rs
@@ -91,7 +91,7 @@ mod tests {
     #[test]
     fn mini() {
         let mut p = PLL::default();
-        let (y, f) = p.update(0x10000, 8, 4);
+        let (y, f) = p.update(Some(0x10000), 8, 4);
         assert_eq!(y, 0x1100);
         assert_eq!(f, y);
     }
@@ -105,7 +105,7 @@ mod tests {
         let mut x = 0i32;
         for i in 0..n {
             x = x.wrapping_add(f0);
-            let (y, f) = p.update(x, shift.0, shift.1);
+            let (y, f) = p.update(Some(x), shift.0, shift.1);
             if i > n / 4 {
                 assert_eq!(f.wrapping_sub(f0).abs() <= 1, true);
             }