diff --git a/src/cpu.rs b/src/cpu.rs
index f78bf7d..a817b05 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -610,29 +610,18 @@ impl<M: Bus, V: Variant> CPU<M, V> {
         }
     }
 
-    fn set_flags_from_i8(status: &mut Status, value: i8) {
-        let is_zero = value == 0;
-        let is_negative = value < 0;
-
-        status.set_with_mask(
-            Status::PS_ZERO | Status::PS_NEGATIVE,
-            Status::new(StatusArgs {
-                zero: is_zero,
-                negative: is_negative,
-                ..StatusArgs::none()
-            }),
-        );
+    const fn value_is_negative(value: u8) -> bool {
+        value > 127
     }
 
     fn set_flags_from_u8(status: &mut Status, value: u8) {
         let is_zero = value == 0;
-        let is_negative = value > 127;
 
         status.set_with_mask(
             Status::PS_ZERO | Status::PS_NEGATIVE,
             Status::new(StatusArgs {
                 zero: is_zero,
-                negative: is_negative,
+                negative: Self::value_is_negative(value),
                 ..StatusArgs::none()
             }),
         );
@@ -650,7 +639,7 @@ impl<M: Bus, V: Variant> CPU<M, V> {
                 ..StatusArgs::none()
             }),
         );
-        CPU::<M, V>::set_flags_from_i8(status, *p_val as i8);
+        CPU::<M, V>::set_flags_from_u8(status, *p_val);
     }
 
     fn shift_right_with_flags(p_val: &mut u8, status: &mut Status) {
@@ -664,7 +653,7 @@ impl<M: Bus, V: Variant> CPU<M, V> {
                 ..StatusArgs::none()
             }),
         );
-        CPU::<M, V>::set_flags_from_i8(status, *p_val as i8);
+        CPU::<M, V>::set_flags_from_u8(status, *p_val);
     }
 
     fn rotate_left_with_flags(p_val: &mut u8, status: &mut Status) {
@@ -680,7 +669,7 @@ impl<M: Bus, V: Variant> CPU<M, V> {
                 ..StatusArgs::none()
             }),
         );
-        CPU::<M, V>::set_flags_from_i8(status, *p_val as i8);
+        CPU::<M, V>::set_flags_from_u8(status, *p_val);
     }
 
     fn rotate_right_with_flags(p_val: &mut u8, status: &mut Status) {
@@ -696,7 +685,7 @@ impl<M: Bus, V: Variant> CPU<M, V> {
                 ..StatusArgs::none()
             }),
         );
-        CPU::<M, V>::set_flags_from_i8(status, *p_val as i8);
+        CPU::<M, V>::set_flags_from_u8(status, *p_val);
     }
 
     fn set_u8_with_flags(mem: &mut u8, status: &mut Status, value: u8) {
@@ -917,13 +906,12 @@ impl<M: Bus, V: Variant> CPU<M, V> {
         let value_new = val.wrapping_add(1);
         *val = value_new;
 
-        let is_negative = (value_new as i8) < 0;
         let is_zero = value_new == 0;
 
         flags.set_with_mask(
             Status::PS_NEGATIVE | Status::PS_ZERO,
             Status::new(StatusArgs {
-                negative: is_negative,
+                negative: Self::value_is_negative(value_new),
                 zero: is_zero,
                 ..StatusArgs::none()
             }),
@@ -934,13 +922,12 @@ impl<M: Bus, V: Variant> CPU<M, V> {
         let value_new = val.wrapping_sub(1);
         *val = value_new;
 
-        let is_negative = (value_new as i8) < 0;
         let is_zero = value_new == 0;
 
         flags.set_with_mask(
             Status::PS_NEGATIVE | Status::PS_ZERO,
             Status::new(StatusArgs {
-                negative: is_negative,
+                negative: Self::value_is_negative(value_new),
                 zero: is_zero,
                 ..StatusArgs::none()
             }),