diff --git a/bash-abbr b/bash-abbr
index 3c859cb..1056501 100644
--- a/bash-abbr
+++ b/bash-abbr
@@ -177,14 +177,14 @@ _redir_or_assign_word () {
     unset -f _redir_or_assign_word
 }
 # shellcheck disable=SC2155
-declare -r _redir_or_assign_word="$(_redir_or_assign_word)" # TODO use bash 5.3 `${}` command substitution syntax to avoid subshells
+declare _redir_or_assign_word="$(_redir_or_assign_word)" # TODO use bash 5.3 `${}` command substitution syntax to avoid subshells
 
 declare -r is_first_word_prefix="($_control_op)[[:blank:]]*((($_redir_or_assign_word)[[:blank:]])*)"
 # If the regex leads to problems/performance issues, you may try this simpler regex
 # that does no redirection/assignment word checking:
 # declare -r is_first_word_prefix="($_control_op)[[:blank:]]*"
 
-unset -v _control_op
+unset -v _control_op _redir_or_assign_word
 
 _try_abbrev_internal () {
     # Recursively perform abbrevation on the line defined by $1, taking $2 as the point and $3 as the mark.