diff --git a/prism/templates/src/diagnostic.c.erb b/prism/templates/src/diagnostic.c.erb
index cedd340e08..6dac751990 100644
--- a/prism/templates/src/diagnostic.c.erb
+++ b/prism/templates/src/diagnostic.c.erb
@@ -100,9 +100,9 @@ static const pm_diagnostic_data_t diagnostic_messages[PM_DIAGNOSTIC_ID_MAX] = {
     [PM_ERR_ARGUMENT_FORWARDING_UNBOUND]        = { "unexpected `...` in an non-parenthesized call", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_ARGUMENT_IN]                        = { "unexpected `in` keyword in arguments", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_ARGUMENT_NO_FORWARDING_AMP]         = { "unexpected `&` when the parent method is not forwarding", PM_ERROR_LEVEL_SYNTAX },
-    [PM_ERR_ARGUMENT_NO_FORWARDING_ELLIPSES]    = { "unexpected `...` when the parent method is not forwarding", PM_ERROR_LEVEL_SYNTAX },
-    [PM_ERR_ARGUMENT_NO_FORWARDING_STAR]        = { "unexpected `*` when the parent method is not forwarding", PM_ERROR_LEVEL_SYNTAX },
-    [PM_ERR_ARGUMENT_NO_FORWARDING_STAR_STAR]   = { "unexpected `**` when the parent method is not forwarding", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_ARGUMENT_NO_FORWARDING_ELLIPSES]    = { "unexpected ... when the parent method is not forwarding", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_ARGUMENT_NO_FORWARDING_STAR]        = { "unexpected `*`; no anonymous rest parameter", PM_ERROR_LEVEL_SYNTAX },
+    [PM_ERR_ARGUMENT_NO_FORWARDING_STAR_STAR]   = { "unexpected `**`; no anonymous keyword rest parameter", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_ARGUMENT_SPLAT_AFTER_ASSOC_SPLAT]   = { "unexpected `*` splat argument after a `**` keyword splat argument", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_ARGUMENT_SPLAT_AFTER_SPLAT]         = { "unexpected `*` splat argument after a `*` splat argument", PM_ERROR_LEVEL_SYNTAX },
     [PM_ERR_ARGUMENT_TERM_PAREN]                = { "expected a `)` to close the arguments", PM_ERROR_LEVEL_SYNTAX },
diff --git a/test/prism/errors_test.rb b/test/prism/errors_test.rb
index 1d9bc0f986..85847982c0 100644
--- a/test/prism/errors_test.rb
+++ b/test/prism/errors_test.rb
@@ -290,14 +290,14 @@ module Prism
 
     def test_argument_forwarding_when_parent_is_not_forwarding
       assert_errors expression('def a(x, y, z); b(...); end'), 'def a(x, y, z); b(...); end', [
-        ["unexpected `...` when the parent method is not forwarding", 18..21]
+        ["unexpected ... when the parent method is not forwarding", 18..21]
       ]
     end
 
     def test_argument_forwarding_only_effects_its_own_internals
       assert_errors expression('def a(...); b(...); end; def c(x, y, z); b(...); end'),
         'def a(...); b(...); end; def c(x, y, z); b(...); end', [
-          ["unexpected `...` when the parent method is not forwarding", 43..46]
+          ["unexpected ... when the parent method is not forwarding", 43..46]
         ]
     end
 
@@ -1054,7 +1054,7 @@ module Prism
       )
 
       assert_errors expected, "->(...) {}", [
-        ["unexpected `...` when the parent method is not forwarding", 3..6]
+        ["unexpected ... when the parent method is not forwarding", 3..6]
       ]
     end
 
@@ -1078,7 +1078,7 @@ module Prism
       )
 
       assert_errors expected, "a {|...|}", [
-        ["unexpected `...` when the parent method is not forwarding", 4..7]
+        ["unexpected ... when the parent method is not forwarding", 4..7]
       ]
     end