diff --git a/modules/user.module b/modules/user.module
index 9ca1db16147..df2e522bbe1 100644
--- a/modules/user.module
+++ b/modules/user.module
@@ -171,7 +171,7 @@ function user_validate_name($name) {
   if (ereg(" \$", $name)) return t("The Username cannot end with a space.");
   if (ereg("  ", $name)) return t("The Username cannot contain multiple spaces in a row.");
   // if (ereg("[^a-zA-Z0-9@-@]", $name)) return t("The Username contains an illegal character.");
-  if (!ereg('^[a-z0-9]+(@[a-z0-9]+)?$', $name)) return t("The name contains an illegal character.");
+  if (!eregi('^[a-z0-9]+(@[a-z0-9]+)?$', $name)) return t("The name contains an illegal character.");
   if (strlen($name) > 56) return t("The Username '$name' is too long: it must be less than 56 characters.");
 }
 
diff --git a/modules/user/user.module b/modules/user/user.module
index 9ca1db16147..df2e522bbe1 100644
--- a/modules/user/user.module
+++ b/modules/user/user.module
@@ -171,7 +171,7 @@ function user_validate_name($name) {
   if (ereg(" \$", $name)) return t("The Username cannot end with a space.");
   if (ereg("  ", $name)) return t("The Username cannot contain multiple spaces in a row.");
   // if (ereg("[^a-zA-Z0-9@-@]", $name)) return t("The Username contains an illegal character.");
-  if (!ereg('^[a-z0-9]+(@[a-z0-9]+)?$', $name)) return t("The name contains an illegal character.");
+  if (!eregi('^[a-z0-9]+(@[a-z0-9]+)?$', $name)) return t("The name contains an illegal character.");
   if (strlen($name) > 56) return t("The Username '$name' is too long: it must be less than 56 characters.");
 }