diff --git a/.claude/scripts/sync.sh b/.claude/scripts/sync.sh
index ff0e173..a2e514e 100755
--- a/.claude/scripts/sync.sh
+++ b/.claude/scripts/sync.sh
@@ -21,12 +21,19 @@ NC='\033[0m'
 # content is never auto-deleted (use `git rm` for that, deliberately).
 purge_garbled_paths() {
     local rec st p removed=0
+    # POSIX ERE (not PCRE): `grep -P` refuses to run under non-UTF-8/unibyte locales on
+    # some platforms (Git Bash printed "grep: -P supports only unibyte and UTF-8 locales",
+    # silently disabling this guard). ERE has no such restriction; LC_ALL=C makes the match
+    # byte-wise. Same byte set as before: control chars / backslash / colon, plus the MSYS2
+    # Private-Use-Area substitutes (0xEE 0x80-0xBF = U+E0xx, 0xEF 0x80-0xA3 = U+F0xx) that
+    # stand in for : \ newline etc. in Windows path-as-filename cruft.
+    local garble_re=$'[\001-\037\\:]|\356[\200-\277]|\357[\200-\243]'
     while IFS= read -r -d '' rec; do
         st="${rec:0:2}"
         p="${rec:3}"
         [ -z "$p" ] && continue
         [ "$st" = "??" ] || continue   # untracked only
-        if printf '%s' "$p" | LC_ALL=C grep -qaP '[\x00-\x1f\\:]|\xee[\x80-\xbf]|\xef[\x80-\xa3]'; then
+        if printf '%s' "$p" | LC_ALL=C grep -qaE "$garble_re"; then
             echo -e "${YELLOW}[WARNING]${NC} Removing garbled untracked path before staging: $(printf '%s' "$p" | cat -v)"
             rm -f -- "$p" 2>/dev/null || true
             removed=1
diff --git a/session-logs/2026-05-25-beast-chrome-fetch-and-identity-audit.md b/session-logs/2026-05-25-beast-chrome-fetch-and-identity-audit.md
index 0180fb1..0a2a975 100644
--- a/session-logs/2026-05-25-beast-chrome-fetch-and-identity-audit.md
+++ b/session-logs/2026-05-25-beast-chrome-fetch-and-identity-audit.md
@@ -125,3 +125,22 @@ another machine has a hyphenated `git config user.name`.
   ("Web Research / Bot-Blocked Sites").
 - Coord reply id: `ac1e3767-f085-4c83-8d74-fbd9cc821d63` (to GURU-5070/claude-main).
 - Extension id `fcoeoabgfenejglbffodgkkbkcdhcgfn`; native host `com.anthropic.claude_browser_extension`.
+
+---
+
+## Update: 13:17 PT — harden sync.sh purge_garbled_paths (locale fix)
+
+During the prior save's sync, `purge_garbled_paths()` printed `grep: -P supports only unibyte and
+UTF-8 locales` — its `grep -P` (PCRE) guard refuses to run on BEAST's Git Bash locale, so the
+garbled-path protection was a silent no-op here.
+
+**Fix:** switched the detector from PCRE (`grep -qaP`) to POSIX ERE (`grep -qaE`), which has no
+such locale restriction, keeping `LC_ALL=C` for byte-wise matching and the **exact same byte set**
+(control chars / `\` / `:` plus the MSYS2 PUA substitutes `0xEE 0x80-0xBF` and `0xEF 0x80-0xA3`).
+Pattern built via `$'...'`. No behavior change other than that it now actually runs.
+
+Verified on BEAST: `bash -n` clean; PUA-garbled name (U+F03A) detected; literal `:` detected;
+normal repo paths not flagged; no `-P` locale error. Applies to all machines on next sync (sync.sh
+is shared).
+
+- File: `.claude/scripts/sync.sh` — `purge_garbled_paths()` grep line + comment.