diff --git a/src/main.rs b/src/main.rs
index dfb7b43..9edd553 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -208,19 +208,16 @@ fn entry() -> Result<(), Error> {
     } else {
         // Decide what to do based on the subcommand.
         match cli.command {
-            // [tag:check_subcommand]
             Some(GramCommand::Check(args)) => {
                 // Check the program.
                 run(Path::new(&args.path), true)?;
             }
 
-            // [tag:run_subcommand]
             Some(GramCommand::Run(args)) => {
                 // Run the program.
                 run(Path::new(&args.path), false)?;
             }
 
-            // [tag:shell_completion_subcommand]
             Some(GramCommand::ShellCompletion(args)) => {
                 shell_completion(&args.shell)?;
             }
diff --git a/toast.yml b/toast.yml
index 7d5bb12..d31887c 100644
--- a/toast.yml
+++ b/toast.yml
@@ -156,6 +156,7 @@ tasks:
 
       # Check references with Tagref.
       tagref
+      tagref list-unused --fail-if-any
 
       # Lint shell files with ShellCheck.
       find . -type f -name '*.sh' | xargs shellcheck