diff --git a/prism/config.yml b/prism/config.yml
index 34cd388f485cb0..5d2c2dbd4971bf 100644
--- a/prism/config.yml
+++ b/prism/config.yml
@@ -1,5 +1,6 @@
 errors:
   - ALIAS_ARGUMENT
+  - ALIAS_ARGUMENT_NUMBERED_REFERENCE
   - AMPAMPEQ_MULTI_ASSIGN
   - ARGUMENT_AFTER_BLOCK
   - ARGUMENT_AFTER_FORWARDING_ELLIPSES
diff --git a/prism/prism.c b/prism/prism.c
index 2a288cae934db0..7527e3c55cf50e 100644
--- a/prism/prism.c
+++ b/prism/prism.c
@@ -16300,7 +16300,7 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power, b
                 case PM_GLOBAL_VARIABLE_READ_NODE: {
                     if (PM_NODE_TYPE_P(old_name, PM_BACK_REFERENCE_READ_NODE) || PM_NODE_TYPE_P(old_name, PM_NUMBERED_REFERENCE_READ_NODE) || PM_NODE_TYPE_P(old_name, PM_GLOBAL_VARIABLE_READ_NODE)) {
                         if (PM_NODE_TYPE_P(old_name, PM_NUMBERED_REFERENCE_READ_NODE)) {
-                            pm_parser_err_node(parser, old_name, PM_ERR_ALIAS_ARGUMENT);
+                            pm_parser_err_node(parser, old_name, PM_ERR_ALIAS_ARGUMENT_NUMBERED_REFERENCE);
                         }
                     } else {
                         pm_parser_err_node(parser, old_name, PM_ERR_ALIAS_ARGUMENT);
diff --git a/prism/templates/src/diagnostic.c.erb b/prism/templates/src/diagnostic.c.erb
index 301f98134f592c..a742c62e8e3355 100644
--- a/prism/templates/src/diagnostic.c.erb
+++ b/prism/templates/src/diagnostic.c.erb
@@ -86,6 +86,7 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = {
 
     // Errors that should raise syntax errors
     [PM_ERR_ALIAS_ARGUMENT]                     = { "invalid argument being passed to `alias`; expected a bare word, symbol, constant, or global variable", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_ALIAS_ARGUMENT_NUMBERED_REFERENCE]  = { "invalid argument being passed to `alias`; can't make alias for the number variables", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_AMPAMPEQ_MULTI_ASSIGN]              = { "unexpected `&&=` in a multiple assignment", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_ARGUMENT_AFTER_BLOCK]               = { "unexpected argument after a block argument", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_ARGUMENT_AFTER_FORWARDING_ELLIPSES] = { "unexpected argument after `...`", PM_ERROR_LEVEL_SYNTAX },