diff --git a/src/protocol/tests/utils.rs b/src/protocol/tests/utils.rs
index 84dde7c2d467633829f7e2df5863b42aee9524b7..fa7153214d697f2f57231e79511d844c581a5442 100644
--- a/src/protocol/tests/utils.rs
+++ b/src/protocol/tests/utils.rs
@@ -405,7 +405,7 @@ impl<'a> EnumTester<'a> {
 
     pub(crate) fn assert_size_alignment(mut self, serialized_monomorph: &str, size: usize, alignment: usize) -> Self {
         self = self.assert_has_monomorph(serialized_monomorph);
-        let (has_monomorph, serialized) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
+        let (has_monomorph, _) = has_monomorph(self.ctx, self.def.this.upcast(), serialized_monomorph);
         let mono_index = has_monomorph.unwrap();
         let mono = self.ctx.types.get_monomorph(mono_index);
 
@@ -753,7 +753,7 @@ impl<'a> VariableTester<'a> {
         let concrete_type = &mono_data.expr_data[self.var_expr.unique_id_in_definition as usize].expr_type;
 
         // Serialize and check
-        let mut serialized = concrete_type.display_name(self.ctx.heap);
+        let serialized = concrete_type.display_name(self.ctx.heap);
 
         assert_eq!(
             expected, &serialized,
@@ -788,7 +788,7 @@ impl<'a> ExpressionTester<'a> {
         let concrete_type = &mono_data.expr_data[expr_index as usize].expr_type;
 
         // Serialize and check type
-        let mut serialized = concrete_type.display_name(self.ctx.heap);
+        let serialized = concrete_type.display_name(self.ctx.heap);
 
         assert_eq!(
             expected, &serialized,
@@ -925,7 +925,6 @@ impl<'a> ErrorTester<'a> {
 
 fn has_equal_num_monomorphs(ctx: TestCtx, num: usize, definition_id: DefinitionId) -> (bool, usize) {
     // Again: inefficient, but its testing code
-    let type_def = ctx.types.get_base_definition(&definition_id).unwrap();
     let mut num_on_type = 0;
 
     for mono in &ctx.types.mono_lookup.monomorphs {