diff --git a/container/src/hledger-flow/lib/lib_preprocess.bash b/container/src/hledger-flow/lib/lib_preprocess.bash
index 9a8d7f8..35421b0 100755
--- a/container/src/hledger-flow/lib/lib_preprocess.bash
+++ b/container/src/hledger-flow/lib/lib_preprocess.bash
@@ -2,7 +2,7 @@
 
 # docker-finance | modern accounting for the power-user
 #
-# Copyright (C) 2021-2025 Aaron Fiore (Founder, Evergreen Crypto LLC)
+# Copyright (C) 2021-2026 Aaron Fiore (Founder, Evergreen Crypto LLC)
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -64,9 +64,16 @@ echo -e "    \e[32m│     └─\e[37;2m ${global_in_filename}\e[0m"
 function lib_preprocess::test_header()
 {
   local _column="$1"
+
   local _header
   _header="$(lib_preprocess::__sanitize_header $2)"
-  [[ "$_header" =~ (^${_column}$|^${_column},|,${_column},|,${_column}$) ]] && return 0 || return 2
+
+  local _delim="$3"
+  [ -z "$_delim" ] && _delim=","
+
+  # TODO: consolidate regexp
+  [[ "$_header" =~ (^"${_column}"$|^"${_column}${_delim}"|"${_delim}${_column}${_delim}"|"${_delim}${_column}"$) ]] \
+    && return 0 || return 2
 }
 
 # Assert header in given CSV header