diff --git a/juniper_codegen/src/derive_input_object.rs b/juniper_codegen/src/derive_input_object.rs
index f5d3c173..512b6121 100644
--- a/juniper_codegen/src/derive_input_object.rs
+++ b/juniper_codegen/src/derive_input_object.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use syn;
 use syn::*;
 use quote::Tokens;
@@ -110,7 +112,7 @@ pub fn impl_input_object(ast: &syn::DeriveInput) -> Tokens {
         let name = match field_attrs.name {
             Some(ref name) => {
                 // Custom name specified.
-                name.to_string()
+                Cow::Borrowed(name.as_ref())
             }
             None => {
                 // Note: auto camel casing when no custom name specified.
diff --git a/juniper_codegen/src/derive_object.rs b/juniper_codegen/src/derive_object.rs
index 51b0dcd4..fd1e6c26 100644
--- a/juniper_codegen/src/derive_object.rs
+++ b/juniper_codegen/src/derive_object.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use syn;
 use syn::*;
 use quote::Tokens;
@@ -106,7 +108,7 @@ pub fn impl_object(ast: &syn::DeriveInput) -> Tokens {
         let name = match field_attrs.name {
             Some(ref name) => {
                 // Custom name specified.
-                name.to_string()
+                Cow::Borrowed(name.as_ref())
             }
             None => {
                 // Note: auto camel casing when no custom name specified.
diff --git a/juniper_codegen/src/util.rs b/juniper_codegen/src/util.rs
index a3096c7b..c10a5050 100644
--- a/juniper_codegen/src/util.rs
+++ b/juniper_codegen/src/util.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use syn::*;
 
 pub fn get_graphl_attr(attrs: &Vec<Attribute>) -> Option<&Vec<NestedMetaItem>> {
@@ -44,12 +46,12 @@ pub fn keyed_item_value(item: &NestedMetaItem, name: &str, must_be_string: bool)
 
 // Note: duplicated from juniper crate!
 #[doc(hidden)]
-pub fn to_camel_case(s: &str) -> String {
-    let mut dest = String::new();
+pub fn to_camel_case<'a>(s: &'a str) -> Cow<'a, str> {
+    let mut dest = Cow::Borrowed(s);
 
     for (i, part) in s.split('_').enumerate() {
         if i > 0 && part.len() == 1 {
-            dest.push_str(&part.to_uppercase());
+            dest += Cow::Owned(part.to_uppercase());
         } else if i > 0 && part.len() > 1 {
             let first = part.chars()
                 .next()
@@ -58,10 +60,10 @@ pub fn to_camel_case(s: &str) -> String {
                 .collect::<String>();
             let second = &part[1..];
 
-            dest.push_str(&first);
-            dest.push_str(second);
+            dest += Cow::Owned(first);
+            dest += second;
         } else if i == 0 {
-            dest.push_str(part);
+            dest = Cow::Borrowed(part);
         }
     }