diff --git a/bash-abbr b/bash-abbr
index c1b0c0a..d0bbb37 100644
--- a/bash-abbr
+++ b/bash-abbr
@@ -150,8 +150,8 @@ _redir_or_assign_word () {
                _double_quoted_string='\$?"([^"]|\\")*"' \
                _single_quoted_string="\\\$?'[^']*'" \
                _backtick_string='`([^`]|\\`)*`' \
-               _simple_variable='\$[[:alpha:]_][[:alnum:]]*' \
-               _advanced_variable='\$\{([[:alnum:]]+|[#-_$!*#])[^{}]*\}' \
+               _simple_variable='\$([[:alpha:]_][[:alnum:]]*|[-_$!*#[:digit:]])' \
+               _advanced_variable='\$\{([[:alpha:]_][[:alnum:]]*|[-_$!*#[:digit:]])[^}]*\}' \
                _deprecated_arithmetic_eval='\$\[[^][]*\]' \
                _cmd_subst_or_arithmetic_eval='\$\([^()]*\)' \
                _process_substition='<\([^()]*\)' \