diff --git a/src/internal/compact/steady.zig b/src/internal/compact/steady.zig
index 9408add..97cc1f6 100644
--- a/src/internal/compact/steady.zig
+++ b/src/internal/compact/steady.zig
@@ -135,6 +135,12 @@ pub const Compactor = struct {
         // boot time, so a compactor that never completes a pass shows as
         // growing age rather than a healthy-looking zero
         self.publishLastPassNow();
+        // the loop below has silent return paths (Canceled propagation); a
+        // compactor that stops running must never do so invisibly — zero
+        // passes over 4+ days went unexplained twice (2026-08-09) because
+        // nothing distinguished "waiting" from "exited"
+        log.info("compactor timer loop running (interval {d}s)", .{self.interval_ns / std.time.ns_per_s});
+        defer log.warn("compactor timer loop exited (no further passes will run)", .{});
         const interval: Io.Clock.Duration = .{
             .raw = Io.Duration.fromNanoseconds(@intCast(self.interval_ns)),
             .clock = .awake,