diff --git a/.dockerignore b/.dockerignore
index 3522d5b..fd9fbce 100644
--- a/.dockerignore
+++ b/.dockerignore
@@ -2,7 +2,6 @@
 .claude
 .DS_Store
 sfdupes
-files.dat
 *.log
 *.out
 *.test
diff --git a/.gitignore b/.gitignore
index fe37e88..56ba247 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,7 +27,6 @@ node_modules/
 *.log
 
 # Local scan data
-files.dat
 *.sqlite
 *.sqlite-shm
 *.sqlite-wal
diff --git a/Makefile b/Makefile
index 57bd44e..67c7260 100644
--- a/Makefile
+++ b/Makefile
@@ -46,4 +46,4 @@ hooks:
 	@script/install-precommit
 
 clean:
-	rm -f $(BINARY) files.dat
+	rm -f $(BINARY)
diff --git a/TODO.md b/TODO.md
index 3da0b6c..e5bff64 100644
--- a/TODO.md
+++ b/TODO.md
@@ -29,6 +29,11 @@
 
 # Completed Steps
 
+- remove the dead `files.dat` references from `Makefile`, `.gitignore`
+  and `.dockerignore` (2026-09-21, branch `next`, closes
+  https://git.eeqj.de/sneak/sfdupes/issues/22): `make clean` still
+  removes the binary; the `.sqlite`/`-shm`/`-wal` ignores remain.
+
 - fix the lint-image pin comments and `FROM` form in `Dockerfile` and
   `Dockerfile.lint` (2026-08-10, branch `next`, closes
   https://git.eeqj.de/sneak/sfdupes/issues/25): dropped the false