diff --git a/container/src/hledger-flow/lib/lib_preprocess.bash b/container/src/hledger-flow/lib/lib_preprocess.bash
index 5ac819c..35421b0 100755
--- a/container/src/hledger-flow/lib/lib_preprocess.bash
+++ b/container/src/hledger-flow/lib/lib_preprocess.bash
@@ -64,10 +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 $2)"
-  # TODO: add custom delim
-  [[ "$_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