diff --git a/tamer/src/diagnose/report.rs b/tamer/src/diagnose/report.rs
index 644a9193..2b995719 100644
--- a/tamer/src/diagnose/report.rs
+++ b/tamer/src/diagnose/report.rs
@@ -508,7 +508,7 @@ impl<'s, 'd> Section<'d> {
     ///  gutter width is 2
     /// ```
     fn gutter_text_width(&self) -> usize {
-        self.line_max.log10().add(1).max(2) as usize
+        self.line_max.ilog10().add(1).max(2) as usize
     }
 }
 
diff --git a/tamer/src/lib.rs b/tamer/src/lib.rs
index 35a438b0..ea3c93a3 100644
--- a/tamer/src/lib.rs
+++ b/tamer/src/lib.rs
@@ -57,6 +57,10 @@
 // Convenience features that are easily replaced if not stabalized.
 #![feature(nonzero_min_max)]
 #![feature(nonzero_ops)]
+// Note: this is the first time TAMER was hit by a change in an unstable
+//   feature,
+//     when `log10` et al. were renamed to `ilog10` et al:
+//       <https://github.com/rust-lang/rust/pull/100332>
 #![feature(int_log)]
 // Used for const params like `&'static str` in `crate::fmt`.
 // If this is not stabalized,