diff --git a/.github/workflows/zsh-n.yml b/.github/workflows/zsh-n.yml
index a1343b3..35a47b1 100644
--- a/.github/workflows/zsh-n.yml
+++ b/.github/workflows/zsh-n.yml
@@ -9,6 +9,7 @@ on:
     paths:
       - "zi.zsh"
       - "lib/**"
+      - "tests/annex-unregister.zsh"
       - "tests/archive-extraction.zsh"
       - "tests/completion-refresh.zsh"
       - "tests/hook-ownership.zsh"
@@ -33,6 +34,7 @@ on:
     paths:
       - "zi.zsh"
       - "lib/**"
+      - "tests/annex-unregister.zsh"
       - "tests/archive-extraction.zsh"
       - "tests/completion-refresh.zsh"
       - "tests/hook-ownership.zsh"
@@ -230,6 +232,17 @@ jobs:
       - name: Test scheduler idle behavior
         run: zsh -f tests/scheduler-idle.zsh
 
+  annex-unregister:
+    name: Annex Unregister
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
+      - name: Install Zsh
+        run: sudo apt update && sudo apt-get install -yq zsh
+      - name: Test annex unregister
+        run: zsh -f tests/annex-unregister.zsh
+
   archive-extraction:
     name: Archive extraction
     runs-on: ubuntu-latest
diff --git a/tests/annex-unregister.zsh b/tests/annex-unregister.zsh
new file mode 100644
index 0000000..bec1fb0
--- /dev/null
+++ b/tests/annex-unregister.zsh
@@ -0,0 +1,100 @@
+#!/usr/bin/env zsh
+# -*- mode: zsh; sh-indentation: 2; indent-tabs-mode: nil; sh-basic-offset: 2; -*-
+# vim: ft=zsh sw=2 ts=2 et
+
+builtin emulate -R zsh
+setopt pipe_fail
+
+fail() {
+  builtin print -u2 -r -- "not ok - $1"
+  exit 1
+}
+
+typeset project_root="${ZI_TEST_CHECKOUT:-${0:A:h:h}}"
+typeset temp_root
+temp_root="$(command mktemp -d "${TMPDIR:-/tmp}/zi-annex-unregister-test.XXXXXXXX")" ||
+  fail "create temporary directory"
+trap 'command rm -rf -- "$temp_root"' EXIT INT TERM
+
+command mkdir -p \
+  "${temp_root}/home" \
+  "${temp_root}/cache" \
+  "${temp_root}/config" \
+  "${temp_root}/data" \
+  "${temp_root}/zdotdir" \
+  "${temp_root}/first" \
+  "${temp_root}/second" || fail "create isolated environment"
+
+builtin print -r -- 'builtin print -r -- first-loaded' \
+  > "${temp_root}/first/first.plugin.zsh" || fail "write the first plug-in"
+builtin print -r -- 'builtin print -r -- second-loaded' \
+  > "${temp_root}/second/second.plugin.zsh" || fail "write the second plug-in"
+
+env \
+  HOME="${temp_root}/home" \
+  XDG_CACHE_HOME="${temp_root}/cache" \
+  XDG_CONFIG_HOME="${temp_root}/config" \
+  XDG_DATA_HOME="${temp_root}/data" \
+  ZDOTDIR="${temp_root}/zdotdir" \
+  ZI_TEST_CHECKOUT="$project_root" \
+  ZI_TEST_ROOT="$temp_root" \
+  zsh -f <<'ZSH' || fail "an unregistered annex hook still affects later plug-in loads"
+builtin emulate -R zsh
+setopt pipe_fail
+
+builtin source "${ZI_TEST_CHECKOUT}/zi.zsh" || return 1
+.zi-prepare-home || return 1
+
+# Unregistering something never registered is a no-op, not an error.
+@zi-unregister-annex never-registered hook:before-load-2 || {
+  builtin print -u2 -r -- "unregistering an absent annex reported an error"
+  return 1
+}
+
+probe_annex_handler() { return 0; }
+@zi-register-annex probe-annex hook:before-load-2 probe_annex_handler '' ''
+
+# The Plugin Standard unload contract has the annex remove its own handler.
+# Without a matching unregister the ZI_EXTS entry survives, the before-load
+# dispatch calls a name that no longer exists, and the resulting 127 is folded
+# into the return value and shifts the argument list for the rest of the
+# session.
+@zi-unregister-annex probe-annex hook:before-load-2
+unfunction probe_annex_handler
+
+typeset output status_first status_second
+output="$(zi load "${ZI_TEST_ROOT}/first" 2>&1)"
+status_first=$?
+[[ $status_first -eq 0 ]] || {
+  builtin print -u2 -r -- "loading after unregister returned ${status_first}: ${output}"
+  return 1
+}
+[[ $output == *first-loaded* ]] || {
+  builtin print -u2 -r -- "the first plug-in did not load: ${output}"
+  return 1
+}
+
+# A second load proves the argument list was not shifted by the first.
+output="$(zi load "${ZI_TEST_ROOT}/second" 2>&1)"
+status_second=$?
+[[ $status_second -eq 0 ]] || {
+  builtin print -u2 -r -- "the second load returned ${status_second}: ${output}"
+  return 1
+}
+[[ $output == *second-loaded* ]] || {
+  builtin print -u2 -r -- "the second plug-in did not load: ${output}"
+  return 1
+}
+
+# The registry itself no longer holds the entry.
+typeset key found=0
+for key in "${(@k)ZI_EXTS}"; do
+  [[ ${ZI_EXTS[$key]} == *probe_annex_handler* ]] && found=1
+done
+(( found == 0 )) || {
+  builtin print -u2 -r -- "a ZI_EXTS entry for the unregistered annex survived"
+  return 1
+}
+ZSH
+
+builtin print -r -- "ok - an unregistered annex hook is removed and later plug-in loads are unaffected"
diff --git a/zi.zsh b/zi.zsh
index f81e5b5..2e8ae22 100644
--- a/zi.zsh
+++ b/zi.zsh
@@ -1283,6 +1283,49 @@ builtin setopt no_aliases
     ZI_EXTS[ice-mods]="${ZI_EXTS[ice-mods]}${icemods:+|}${(j:|:)${(@)${(@s:|:)icemods}/(#b)(#s)(?)/$index-$match[1]}}"
   }
 } # ]]]
+# FUNCTION: @zi-unregister-annex. [[[
+# Removes the registrations made by @zi-register-annex and @zi-register-hook for
+# one annex and one hook type, so an annex can remove its handler as the Zsh
+# Plugin Standard unload contract expects without leaving Zi dispatching to a
+# function that no longer exists.
+#
+# A stale registration is not inert. The before-load dispatch calls the stored
+# handler unconditionally, a missing function returns 127, and `127 & 1' is true,
+# so Zi folds the error into its return value and shifts its argument list on
+# every later plug-in load in the session.
+#
+# Unregistering something that was never registered is a no-op.
+#
+# Note: the ice-modifier list each registration contributed to
+# ZI_EXTS[ice-mods] and ZI_EXTS2[ice-mods] is not unwound. Registration appends
+# to a joined string without recording which annex contributed which entry, so
+# removing one annex's share would need that association to be recorded first.
+# A leftover ice name is recognised but dispatches to nothing, which is
+# harmless; the dispatch entry removed here is the part that corrupts loads.
+@zi-unregister-annex() {
+  builtin emulate -LR zsh ${=${options[xtrace]:#off}:+-o xtrace}
+  builtin setopt extended_glob no_bang_hist typeset_silent
+
+  local name="$1" type="$2" ___key
+  local -a ___arr ___doomed
+
+  for ___key in "${(@k)ZI_EXTS}"; do
+    [[ $___key == (seqno|ice-mods) ]] && continue
+    ___arr=( "${(Q)${(z@)ZI_EXTS[$___key]}[@]}" )
+    [[ ${___arr[3]} == $name && ${___arr[4]} == $type ]] && ___doomed+=( "$___key" )
+  done
+  (( ${#___doomed} )) && unset "ZI_EXTS[${^___doomed[@]}]"
+
+  ___doomed=( )
+  for ___key in "${(@k)ZI_EXTS2}"; do
+    [[ $___key == (seqno|ice-mods) ]] && continue
+    ___arr=( "${(Q)${(z@)ZI_EXTS2[$___key]}[@]}" )
+    [[ ${___arr[3]} == $name && ${___arr[4]} == $type ]] && ___doomed+=( "$___key" )
+  done
+  (( ${#___doomed} )) && unset "ZI_EXTS2[${^___doomed[@]}]"
+
+  return 0
+} # ]]]
 # FUNCTION: @zi-register-hook. [[[
 # Registers the z-annex inside Zi.
 @zi-register-hook() {