diff --git a/src/libsyntax/diagnostics/macros.rs b/src/libsyntax/diagnostics/macros.rs
index 055ade46a3f01..8c2d2a251aab8 100644
--- a/src/libsyntax/diagnostics/macros.rs
+++ b/src/libsyntax/diagnostics/macros.rs
@@ -63,6 +63,9 @@ macro_rules! fileline_help {
 macro_rules! register_diagnostics {
     ($($code:tt),*) => (
         $(register_diagnostic! { $code })*
+    );
+    ($($code:tt),*,) => (
+        $(register_diagnostic! { $code })*
     )
 }