diff --git a/.claude/hooks/guard-taboos-test.sh b/.claude/hooks/guard-taboos-test.sh
index 9c940e6..857f2a6 100755
--- a/.claude/hooks/guard-taboos-test.sh
+++ b/.claude/hooks/guard-taboos-test.sh
@@ -456,6 +456,15 @@ check deny 'vi /etc/heinzel.conf'
 check deny 'ssh root@h "rm /etc/heinzel.conf"'
 check deny 'ssh root@h "sed -i s/false/true/ /etc/heinzel.conf"'
 check deny 'python3 -c "import os; os.remove(\"/etc/heinzel.conf\")"'
+# Other spellings of the same file: a case-insensitive filesystem
+# (macOS), // and /./, a relative path after cd, find -delete.
+check deny 'rm /ETC/HEINZEL.CONF'
+check deny 'rm /etc//heinzel.conf'
+check deny 'rm /etc/./heinzel.conf'
+check deny 'cd /etc && rm heinzel.conf'
+check deny 'cd /etc; echo allow_changes=true > heinzel.conf'
+check deny 'find /etc -name heinzel.conf -delete'
+check deny 'ln -sf /dev/null /etc/heinzel.conf'
 check pass 'cat /etc/heinzel.conf'
 check pass 'ssh root@h "cat /etc/heinzel.conf"'
 check pass 'ssh root@h "if [ -e /etc/heinzel.conf ]; then cat /etc/heinzel.conf || echo HEINZEL_CONF_UNREADABLE; else echo HEINZEL_CONF_ABSENT; fi"'
diff --git a/.claude/hooks/guard-taboos.sh b/.claude/hooks/guard-taboos.sh
index 086d1c7..9983469 100755
--- a/.claude/hooks/guard-taboos.sh
+++ b/.claude/hooks/guard-taboos.sh
@@ -362,9 +362,14 @@ EFIVARS='/sys/firmware/efi/efivars'
 
 # The server lock. The machine's owner writes it to keep heinzel
 # hands-off; a heinzel that could flip it to true or delete it
-# would make it worthless. Unanchored on the left, so macOS's
-# /private/etc matches too. Reading it stays allowed.
-LOCKFILE='/etc/heinzel\.conf'
+# would make it worthless. Matched by its file name alone, in any
+# case: the full path misses /ETC/HEINZEL.CONF on macOS, /etc//
+# and /etc/./, and a relative heinzel.conf after cd /etc. A write
+# to any file of that name is denied with it. Not closable: a
+# glob (/etc/heinzel.c*) or a name built at run time still gets
+# through, so the written rule stays the first line of defence.
+# Reading it stays allowed.
+LOCKFILE='[Hh][Ee][Ii][Nn][Zz][Ee][Ll]\.[Cc][Oo][Nn][Ff]'
 
 # A general-purpose language runtime. See the interpreter section
 # at the bottom for why this list, and not a list of the ways
@@ -970,8 +975,9 @@ account work is a Heinzel Pro feature"
 fi
 
 # --- The server lock ------------------------------------------
-# Same write set as sudoers above: a redirect, sed -i, an editor,
-# a delete, move or re-permission, a copy or tee onto it. Moving
+# Same write set as sudoers above (a redirect, sed -i, an editor,
+# a delete, move or re-permission, a copy or tee onto it), plus
+# find -delete, which deletes by a name it never spells as a path. Moving
 # or deleting it lifts the lock as surely as writing true.
 if hit "$LOCKFILE"; then
   if hit '>>?[[:space:]]*["'\'']?[^[:space:];|&]*'"$LOCKFILE" \
@@ -979,6 +985,7 @@ if hit "$LOCKFILE"; then
          && hit '(^|[[:space:]])-i'; } \
     || hit "(^|[^[:alnum:]_-])$EDITOR([^[:alnum:]_-]|\$)" \
     || hit "(^|[^[:alnum:]_-])($CLOBBER|cp)([^[:alnum:]_-]|\$)" \
+    || hit '(^|[[:space:]])-delete([[:space:]]|$)' \
     || writes_to "$LOCKFILE"
   then
     deny "/etc/heinzel.conf is the server lock; only the \
diff --git a/CHANGELOG.md b/CHANGELOG.md
index eeb4e77..92bdb5c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 3.1.1 — 2026-10-15
+
+- **The server lock holds under other spellings.** The
+  guard now matches `heinzel.conf` by name in any case,
+  so `/ETC/HEINZEL.CONF` on macOS, `/etc//heinzel.conf`
+  and a relative path after `cd /etc` are blocked too,
+  and so is `find … -delete`.
+
 ## 3.1.0 — 2026-10-15
 
 - **A server can lock itself.** `allow_changes = false`
diff --git a/VERSION b/VERSION
index fd2a018..94ff29c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-3.1.0
+3.1.1