diff --git a/src/etc/emacs/rust-mode.el b/src/etc/emacs/rust-mode.el
index 580e5f89cd4e0..1312fd6a6023d 100644
--- a/src/etc/emacs/rust-mode.el
+++ b/src/etc/emacs/rust-mode.el
@@ -217,7 +217,7 @@
       1 font-lock-preprocessor-face)
 
      ;; Syntax extension invocations like `foo!`, highlight including the !
-     (,(concat (rust-re-grab (concat rust-re-ident "!")) "[({[:space:]]")
+     (,(concat (rust-re-grab (concat rust-re-ident "!")) "[([{[:space:]]")
       1 font-lock-preprocessor-face)
 
      ;; Field names like `foo:`, highlight excluding the :