diff --git a/rust/src/filter/parser.rs b/rust/src/filter/parser.rs
index 4e9b08e..ef0bf3d 100644
--- a/rust/src/filter/parser.rs
+++ b/rust/src/filter/parser.rs
@@ -375,8 +375,7 @@ fn split_num(s: &str) -> (&str, &str) {
 pub fn parse_size(s: &str) -> Result<i64, String> {
     let (num, unit_raw) = split_num(s);
     let Ok(v) = num.parse::<f64>() else { return Err(format!("bad size {s:?}")) };
-    // ponytail: textutil exposes no SI getter; its formatting reveals the setting.
-    let bare: f64 = if crate::textutil::size(1000).ends_with("kB") { 1000.0 } else { 1024.0 };
+    let bare: f64 = if crate::textutil::si() { 1000.0 } else { 1024.0 };
     let m = match unit_raw.trim().to_lowercase().as_str() {
         "" | "b" => 1.0,
         "k" => bare,
diff --git a/rust/src/textutil.rs b/rust/src/textutil.rs
index a4c496e..a64cea0 100644
--- a/rust/src/textutil.rs
+++ b/rust/src/textutil.rs
@@ -162,11 +162,16 @@ pub fn set_si(v: bool) {
     SI.store(v, Ordering::Relaxed);
 }
 
+/// Whether decimal units are selected.
+pub fn si() -> bool {
+    SI.load(Ordering::Relaxed)
+}
+
 const IEC_UNITS: [&str; 7] = ["B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB"];
 const SI_UNITS: [&str; 7] = ["B", "kB", "MB", "GB", "TB", "PB", "EB"];
 
 fn scaled(n: i64) -> (f64, &'static str) {
-    let (base, units) = if SI.load(Ordering::Relaxed) { (1000.0, &SI_UNITS) } else { (1024.0, &IEC_UNITS) };
+    let (base, units) = if si() { (1000.0, &SI_UNITS) } else { (1024.0, &IEC_UNITS) };
     let neg = n < 0;
     let mut v = (n as f64).abs();
     let mut i = 0;