diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a1ac7a5c..65e051d4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -64,7 +64,7 @@ jobs:
         run: script/build-wasm
 
       - name: Build CLI
-        run: cargo build --release
+        run: RUSTFLAGS="-D warnings" cargo build --release
 
       - name: Set up fixture parsers
         run: |
diff --git a/cli/src/generate/build_tables/item.rs b/cli/src/generate/build_tables/item.rs
index fc167151..32b1a8d9 100644
--- a/cli/src/generate/build_tables/item.rs
+++ b/cli/src/generate/build_tables/item.rs
@@ -75,7 +75,6 @@ pub(crate) struct TokenSetDisplay<'a>(
     pub &'a LexicalGrammar,
 );
 
-#[allow(dead_code)]
 pub(crate) struct ParseItemSetDisplay<'a>(
     pub &'a ParseItemSet<'a>,
     pub &'a SyntaxGrammar,
@@ -181,7 +180,6 @@ impl<'a> Default for ParseItemSet<'a> {
     }
 }
 
-#[allow(dead_code)]
 impl<'a> fmt::Display for ParseItemDisplay<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
         if self.0.is_augmented() {