diff --git a/func/main.sh b/func/main.sh
index 48ff7bf2..3703c0af 100644
--- a/func/main.sh
+++ b/func/main.sh
@@ -556,7 +556,7 @@ validate_format_email() {
 
 # Username
 validate_format_username() {
-    if ! [[ "$1" =~ ^[a-zA-Z0-9]+([\.|_|-][a-zA-Z0-9]+)?$ ]]; then
+    if ! [[ "$1" =~ ^[[:alnum:]]+([\.|_|-][[:alnum:]]+)?$ ]]; then
         echo "Error: $2 $1 is not valid"
         log_event "$E_INVALID" "$EVENT"
         exit $E_INVALID