2 files changed, 10 insertions, 8 deletions
diff --git a/src/diag.rs b/src/diag.rs
index c1a7c834..88141062 100644
--- a/src/diag.rs
+++ b/src/diag.rs
@@ -249,31 +249,31 @@ impl From<FileError> for EcoString {
 }
 
 /// Format a user-facing error message for an XML-like file format.
-pub fn format_xml_like_error(format: &str, error: roxmltree::Error) -> String {
+pub fn format_xml_like_error(format: &str, error: roxmltree::Error) -> EcoString {
     match error {
         roxmltree::Error::UnexpectedCloseTag { expected, actual, pos } => {
-            format!(
+            eco_format!(
                 "failed to parse {format}: found closing tag '{actual}' \
                  instead of '{expected}' in line {}",
                 pos.row
             )
         }
         roxmltree::Error::UnknownEntityReference(entity, pos) => {
-            format!(
+            eco_format!(
                 "failed to parse {format}: unknown entity '{entity}' in line {}",
                 pos.row
             )
         }
         roxmltree::Error::DuplicatedAttribute(attr, pos) => {
-            format!(
+            eco_format!(
                 "failed to parse {format}: duplicate attribute '{attr}' in line {}",
                 pos.row
             )
         }
         roxmltree::Error::NoRootNode => {
-            format!("failed to parse {format}: missing root node")
+            eco_format!("failed to parse {format}: missing root node")
         }
         roxmltree::Error::SizeLimit => "file is too large".into(),
-        _ => format!("failed to parse {format}"),
+        _ => eco_format!("failed to parse {format}"),
     }
 }
diff --git a/src/image.rs b/src/image.rs
index 44b00adb..23ea60f5 100644
--- a/src/image.rs
+++ b/src/image.rs
@@ -3,6 +3,8 @@
 use std::io;
 use std::sync::Arc;
 
+use ecow::EcoString;
+
 use crate::diag::{format_xml_like_error, StrResult};
 use crate::util::Buffer;
 
@@ -152,7 +154,7 @@ fn determine_size(data: &Buffer, format: ImageFormat) -> StrResult<(u32, u32)> {
 }
 
 /// Format the user-facing raster graphic decoding error message.
-fn format_image_error(error: image::ImageError) -> String {
+fn format_image_error(error: image::ImageError) -> EcoString {
     match error {
         image::ImageError::Limits(_) => "file is too large".into(),
         _ => "failed to decode image".into(),
@@ -160,7 +162,7 @@ fn format_image_error(error: image::ImageError) -> String {
 }
 
 /// Format the user-facing SVG decoding error message.
-fn format_usvg_error(error: usvg::Error) -> String {
+fn format_usvg_error(error: usvg::Error) -> EcoString {
     match error {
         usvg::Error::NotAnUtf8Str => "file is not valid utf-8".into(),
         usvg::Error::MalformedGZip => "file is not compressed correctly".into(),