diff --git a/lib/lib_sanitizer.sh b/lib/lib_sanitizer.sh
index 116d01e..e07a127 100644
--- a/lib/lib_sanitizer.sh
+++ b/lib/lib_sanitizer.sh
@@ -35,22 +35,23 @@ arg_check() {
 sanitize_arg() {
   declare input="$1"
   # Define allowed characters:
-  # letters, digits, dot, underscore, slash, equals, [, ], colon, double-quote, hyphen, space.
-  declare allowed='a-zA-Z0-9._/=\[\]:"\- '
+  # letters, digits, dot, underscore, slash, equals, [, ], colon, double-quote, hyphen, plus, space.
+  declare allowed
   declare disallowed
-  disallowed=$(printf '%s' "${input}" | tr -d "${allowed}")
+  allowed='a-zA-Z0-9._/=[]:"-+ '
+  disallowed=$(printf '%s' "$input" | sed "s/[$allowed]//g")
 
   if [[ -n ${disallowed} ]]; then
     {
       printf "❌ Invalid character   : '%s'. \n" "${disallowed//?/& }"
       printf "❌         in argument : '%s'. \n" "${input}"
-      printf "❌ Allowed Characters  : 'a-z A-Z 0-9 . _ / = [ ] : \" - ' \n"
+      printf "❌ Allowed Characters  : 'a-z A-Z 0-9 . _ / = [ ] : \" - + space' \n"
       printf "\n"
     } >> "${LOG_ERROR}"
     boot_screen_cleaner
     printf "\e[91m❌ Invalid character   : '%s'. \e[0m\n" "${disallowed//?/& }" >&2
     printf "\e[91m❌         in argument : '%s'. \e[0m\n" "${input}" >&2
-    printf "\e[91m❌ Allowed Characters  : 'a-z A-Z 0-9 . _ / = [ ] : \" - ' \e[0m\n" >&2
+    printf "\e[91m❌ Allowed Characters  : 'a-z A-Z 0-9 . _ / = [ ] : \" - + space' \e[0m\n" >&2
     # shellcheck disable=SC2162
     read -p  $'\e[92m✅ Press \'ENTER\' to exit the script ... \e[0m'
     exit "${ERR_INVLD_CHAR}"