diff --git a/docs/matrix.md b/docs/matrix.md
index 5c27216f..167ff14d 100644
--- a/docs/matrix.md
+++ b/docs/matrix.md
@@ -250,7 +250,7 @@ Both fixed in `nix/host-modules/hive-matrix.nix` via two derivations:
   incremental cost) and (b) installs `fluffychat-web-imaging`'s
   outputs into `$out`.
 
-Two non-obvious fixes from review history:
+Two non-obvious details worth knowing before touching either derivation:
 
 - **`make -C js`** instead of `cd js; make` — keeps the build-phase
   pwd at the source root so `installPhase` doesn't have to know