diff --git a/extension.toml b/extension.toml
index 6eaa872..4b1a52f 100644
--- a/extension.toml
+++ b/extension.toml
@@ -8,7 +8,7 @@ repository = "https://github.com/graphcal-lang/zed-graphcal"
 
 [grammars.graphcal]
 repository = "https://github.com/graphcal-lang/tree-sitter-graphcal"
-rev = "63c11f26a58c34e0e649ca4889eeb38ed49afdec"
+rev = "b1bb618db937ca310a8851d142c951900d80f5be"
 
 [language_servers.graphcal-lsp]
 name = "Graphcal LSP"
diff --git a/languages/graphcal/highlights.scm b/languages/graphcal/highlights.scm
index 25267b2..2dc014e 100644
--- a/languages/graphcal/highlights.scm
+++ b/languages/graphcal/highlights.scm
@@ -45,6 +45,9 @@
 ; in `import plugin "…"` to an anonymous "plugin" node.
 (plugin_import_declaration "plugin" @keyword)
 
+; Only the node-definition marker is a keyword; ordinary `todo` names are not.
+(todo_definition "todo" @keyword)
+
 ; ---------------------------------------------------------------
 ; Literals
 ; ---------------------------------------------------------------