diff --git a/src/compile.rs b/src/compile.rs
index f5684584..2019623d 100644
--- a/src/compile.rs
+++ b/src/compile.rs
@@ -136,7 +136,7 @@ fn map_annotation_info(
             return false;
         }
     };
-    let annotations = annotation_map.entry(key).or_insert_with(BTreeSet::new);
+    let annotations = annotation_map.entry(key).or_default();
     if !annotation_infos.is_empty() {
         annotations.append(&mut annotation_infos);
     }
diff --git a/src/context.rs b/src/context.rs
index f32899e3..0c8250e0 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -1,6 +1,5 @@
 // Copyright (c) Microsoft Corporation.
 // SPDX-License-Identifier: MIT
-use std::borrow::Borrow;
 use std::collections::BTreeMap;
 use std::iter;
 use std::ops::Range;
@@ -96,7 +95,7 @@ impl<'a> Context<'a> {
         let arg = self.convert_arg_this(arg);
         match self.symbols.get(&CascadeString::from(&arg as &str)) {
             Some(b) => match b {
-                BindableObject::Type(t) => Some(t.type_info.borrow()),
+                BindableObject::Type(t) => Some(t.type_info),
                 // TypeList isn't natural to implement with the current API
                 BindableObject::TypeList(_) => todo!(),
                 BindableObject::PermList(_) => type_map.get("perm"),
diff --git a/src/functions.rs b/src/functions.rs
index 43772c9e..acf3e96f 100644
--- a/src/functions.rs
+++ b/src/functions.rs
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: MIT
 use sexp::{atom_s, list, Atom, Sexp};
 
-use std::borrow::{Borrow, Cow};
+use std::borrow::Cow;
 use std::cmp::Ordering;
 use std::collections::{BTreeMap, BTreeSet};
 use std::convert::TryFrom;
@@ -3416,28 +3416,12 @@ impl<'a> ArgForValidation<'a> {
 
         match self {
             ArgForValidation::Var(s) => {
-                validate_cast(
-                    s,
-                    Some(cast_ti.type_info.borrow()),
-                    None,
-                    None,
-                    types,
-                    context,
-                    file,
-                )?;
+                validate_cast(s, Some(cast_ti.type_info), None, None, types, context, file)?;
             }
             ArgForValidation::List(v) => {
                 for s in v {
                     // TODO: report more than just the first error
-                    validate_cast(
-                        s,
-                        Some(cast_ti.type_info.borrow()),
-                        None,
-                        None,
-                        types,
-                        context,
-                        file,
-                    )?;
+                    validate_cast(s, Some(cast_ti.type_info), None, None, types, context, file)?;
                 }
             }
             ArgForValidation::Quote(inner) => {
diff --git a/src/internal_rep.rs b/src/internal_rep.rs
index 7efb160b..1f769156 100644
--- a/src/internal_rep.rs
+++ b/src/internal_rep.rs
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: MIT
 use sexp::{atom_s, list, Sexp};
 
-use std::borrow::{Borrow, Cow};
+use std::borrow::Cow;
 use std::cmp::Ordering;
 use std::collections::{BTreeMap, BTreeSet};
 use std::convert::TryFrom;
@@ -938,7 +938,7 @@ impl<'a> Context<'a> {
         // The global rename_cow works on CascadeStrings.  In this local case we work on &strs
         // instead
         fn rename_cow<'a>(cow_str: &str, renames: &BTreeMap<String, String>) -> Cow<'a, str> {
-            let new_str: &str = cow_str.borrow();
+            let new_str: &str = cow_str;
             Cow::Owned(renames.get(new_str).unwrap_or(&new_str.to_string()).clone())
         }
         Context {