diff --git a/crates/xenia-cpu/src/fpscr.rs b/crates/xenia-cpu/src/fpscr.rs
index 535a500..24ac3ff 100644
--- a/crates/xenia-cpu/src/fpscr.rs
+++ b/crates/xenia-cpu/src/fpscr.rs
@@ -286,7 +286,12 @@ fn round_single_toward_zero(v: f64) -> f32 {
     if rn.is_nan() || rn.is_infinite() || rn == 0.0 { return rn; }
     if rn.abs() as f64 <= v.abs() { return rn; }
     let adj_bits = rn.to_bits();
-    let lower = if rn.is_sign_positive() { adj_bits - 1 } else { adj_bits - 1 };
+    // Both positive and negative finite f32 values have the IEEE-754 sign
+    // bit as the MSB; subtracting 1 from `to_bits()` always reduces the
+    // magnitude by one ULP (clearing the lowest mantissa bit, with carry
+    // never reaching the sign bit since adj_bits is already not-zero,
+    // not-inf, not-NaN, and we already returned early for those).
+    let lower = adj_bits - 1;
     f32::from_bits(lower)
 }