diff --git a/.github/workflows/zsh-n.yml b/.github/workflows/zsh-n.yml
index fbf550d..152105b 100644
--- a/.github/workflows/zsh-n.yml
+++ b/.github/workflows/zsh-n.yml
@@ -13,6 +13,7 @@ on:
       - "tests/atinit-deferred-marker.zsh"
       - "tests/archive-extraction.zsh"
       - "tests/completion-refresh.zsh"
+      - "tests/home-preparation.zsh"
       - "tests/hook-ownership.zsh"
       - "tests/load-object-status.zsh"
       - "tests/message-formatting.zsh"
@@ -40,6 +41,7 @@ on:
       - "tests/atinit-deferred-marker.zsh"
       - "tests/archive-extraction.zsh"
       - "tests/completion-refresh.zsh"
+      - "tests/home-preparation.zsh"
       - "tests/hook-ownership.zsh"
       - "tests/load-object-status.zsh"
       - "tests/message-formatting.zsh"
@@ -291,6 +293,17 @@ jobs:
       - name: Test completion refresh
         run: zsh tests/completion-refresh.zsh
 
+  home-preparation:
+    name: Home Preparation
+    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 home preparation
+        run: zsh -f tests/home-preparation.zsh
+
   hook-ownership:
     name: Hook ownership
     runs-on: ubuntu-latest
diff --git a/tests/home-preparation.zsh b/tests/home-preparation.zsh
new file mode 100644
index 0000000..3b2f463
--- /dev/null
+++ b/tests/home-preparation.zsh
@@ -0,0 +1,98 @@
+#!/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 "${TMPDIR:-/tmp}/zi-home-prep-test.XXXXXXXX")" ||
+  fail "create temporary directory"
+# The failure case makes a directory read-only; restore it so cleanup can work.
+trap 'command chmod -R u+rwX -- "$temp_root" 2>/dev/null; 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" || fail "create isolated environment"
+
+# Running as root would bypass the permission case entirely.
+if [[ ${EUID:-$UID} -eq 0 ]]; then
+  builtin print -r -- "ok - skipped, the permission case is meaningless as root"
+  exit 0
+fi
+
+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" \
+  zsh -f <<'ZSH' || fail "home preparation is not complete, propagating or retryable"
+builtin emulate -R zsh
+setopt pipe_fail
+
+builtin source "${ZI_TEST_CHECKOUT}/zi.zsh" >/dev/null 2>&1 || return 1
+
+# A partial layout. The services directory used to be created only inside the
+# branch guarded on the snippets directory being absent, so a tree with
+# snippets/ present and services/ missing was accepted as ready.
+command rm -rf "${ZI[SERVICES_DIR]}"
+[[ -d ${ZI[SNIPPETS_DIR]} ]] || {
+  builtin print -u2 -r -- "fixture: the snippets directory should still exist"
+  return 1
+}
+unset 'ZI[HOME_READY]'
+.zi-prepare-home || {
+  builtin print -u2 -r -- "partial layout: preparation reported failure"
+  return 1
+}
+[[ -d ${ZI[SERVICES_DIR]} ]] || {
+  builtin print -u2 -r -- "partial layout: the services directory was not created"
+  return 1
+}
+
+# A required directory that cannot be created has to fail, and must not mark the
+# home ready, so a later call can retry.
+command rm -rf "${ZI[SERVICES_DIR]}"
+command chmod 500 "${ZI[HOME_DIR]}"
+unset 'ZI[HOME_READY]'
+.zi-prepare-home 2>/dev/null && {
+  command chmod 700 "${ZI[HOME_DIR]}"
+  builtin print -u2 -r -- "unwritable home: preparation reported success"
+  return 1
+}
+[[ -z ${ZI[HOME_READY]} ]] || {
+  command chmod 700 "${ZI[HOME_DIR]}"
+  builtin print -u2 -r -- "unwritable home: ZI[HOME_READY] was set despite failure"
+  return 1
+}
+
+# Retry after the cause is removed.
+command chmod 700 "${ZI[HOME_DIR]}"
+.zi-prepare-home || {
+  builtin print -u2 -r -- "retry: preparation still reported failure"
+  return 1
+}
+[[ -d ${ZI[SERVICES_DIR]} && -n ${ZI[HOME_READY]} ]] || {
+  builtin print -u2 -r -- "retry: the home was not completed"
+  return 1
+}
+
+# An already-ready home is a cheap no-op.
+.zi-prepare-home || {
+  builtin print -u2 -r -- "second call on a ready home reported failure"
+  return 1
+}
+ZSH
+
+builtin print -r -- "ok - home preparation completes partial layouts, propagates failure and stays retryable"
diff --git a/zi.zsh b/zi.zsh
index 82d749d..6f09b97 100644
--- a/zi.zsh
+++ b/zi.zsh
@@ -1380,8 +1380,7 @@ builtin setopt no_aliases
 # FUNCTION: .zi-prepare-home. [[[
 # Establish all required directories.
 .zi-prepare-home() {
-  [[ -n ${ZI[HOME_READY]} ]] && return
-  ZI[HOME_READY]=1
+  [[ -n ${ZI[HOME_READY]} ]] && return 0
   if [[ ! -d ${ZI[HOME_DIR]} ]]; then
     command mkdir -p "${ZI[HOME_DIR]}"
     command chmod 700 "${ZI[HOME_DIR]}"
@@ -1440,9 +1439,33 @@ builtin setopt no_aliases
     command mkdir -p "${ZI[SNIPPETS_DIR]}/OMZ::plugins"
     command chmod go-w "${ZI[SNIPPETS_DIR]}"
     ( builtin cd -q ${ZI[SNIPPETS_DIR]}; command ln -s OMZ::plugins plugins; )
+  fi
+  # Independently of the snippets directory. These were nested, so a layout with
+  # snippets/ already present and services/ missing, which a migration or a
+  # manual repair can leave behind, never created the services directory and was
+  # still accepted as ready. Service startup then tried to place locks and FIFOs
+  # below a directory that did not exist.
+  if [[ ! -d ${ZI[SERVICES_DIR]} ]]; then
     command mkdir -p "${ZI[SERVICES_DIR]}"
     command chmod go-w "${ZI[SERVICES_DIR]}"
   fi
+  # Validate before declaring the home ready, and leave ZI[HOME_READY] unset on
+  # failure so a later call can retry. $ZPFX and the manual directory stay
+  # best-effort: they are user-facing install prefixes rather than Zi's own
+  # state, and the manual tree has always tolerated a creation failure.
+  local ___required
+  for ___required (
+    ${ZI[HOME_DIR]} ${ZI[CACHE_DIR]} ${ZI[CONFIG_DIR]} ${ZI[LOG_DIR]}
+    ${ZI[ZMODULES_DIR]} ${ZI[PLUGINS_DIR]} ${ZI[PLUGINS_DIR]}/_local---zi
+    ${ZI[COMPLETIONS_DIR]} ${ZI[SNIPPETS_DIR]} ${ZI[SERVICES_DIR]}
+  ) {
+    [[ -d $___required ]] || {
+      builtin print -u2 -r -- "zi: home preparation incomplete, missing: ${___required}"
+      return 1
+    }
+  }
+  ZI[HOME_READY]=1
+  return 0
 } # ]]]
 # FUNCTION: .zi-load-object. [[[
 .zi-load-object() {