diff --git a/src/protocol/tests/utils.rs b/src/protocol/tests/utils.rs
index 072e3601ba67992e8ee3874a49f4f94f6130f906..479a6cc52847075f06be1c25988721c14c95ea39 100644
--- a/src/protocol/tests/utils.rs
+++ b/src/protocol/tests/utils.rs
@@ -120,6 +120,7 @@ impl AstTesterResult {
 // Interface for successful compilation
 //------------------------------------------------------------------------------
 
+#[allow(dead_code)]
 pub(crate) struct AstOkTester {
     test_name: String,
     modules: Vec<Module>,
@@ -949,11 +950,6 @@ fn has_monomorph(ctx: TestCtx, definition_id: DefinitionId, serialized_monomorph
 fn serialize_parser_type(buffer: &mut String, heap: &Heap, parser_type: &ParserType) {
     use ParserTypeVariant as PTV;
 
-    fn write_bytes(buffer: &mut String, bytes: &[u8]) {
-        let utf8 = String::from_utf8_lossy(bytes);
-        buffer.push_str(&utf8);
-    }
-
     fn serialize_variant(buffer: &mut String, heap: &Heap, parser_type: &ParserType, mut idx: usize) -> usize {
         match &parser_type.elements[idx].variant {
             PTV::Void => buffer.push_str("void"),