diff --git a/src/canisters/frontend/ic-asset/src/asset/config.rs b/src/canisters/frontend/ic-asset/src/asset/config.rs
index 64da185366..328eb77586 100644
--- a/src/canisters/frontend/ic-asset/src/asset/config.rs
+++ b/src/canisters/frontend/ic-asset/src/asset/config.rs
@@ -461,6 +461,7 @@ mod with_tempdir {
     #[cfg(target_family = "unix")]
     use std::os::unix::prelude::PermissionsExt;
     use std::{collections::BTreeMap, fs::File};
+    use std::error::Error;
     use tempfile::{Builder, TempDir};
 
     fn create_temporary_assets_directory(
@@ -887,9 +888,9 @@ mod with_tempdir {
 
         let assets_config = AssetSourceDirectoryConfiguration::load(&assets_dir);
         assert_eq!(
-            assets_config.err().unwrap().to_string(),
+            assets_config.as_ref().err().unwrap().to_string(),
             format!(
-                "Failed to read {} as string: Permission denied (os error 13)",
+                "Failed to read {} as string",
                 assets_dir
                     .join(ASSETS_CONFIG_FILENAME_JSON)
                     .as_path()
@@ -897,6 +898,10 @@ mod with_tempdir {
                     .unwrap()
             )
         );
+        assert_eq!(
+            assets_config.err().unwrap().source().unwrap().to_string(),
+            "Permission denied (os error 13)"
+        );
     }
 
     #[test]
diff --git a/src/dfx-core/src/error/config.rs b/src/dfx-core/src/error/config.rs
index 54e19f464d..17eef4e364 100644
--- a/src/dfx-core/src/error/config.rs
+++ b/src/dfx-core/src/error/config.rs
@@ -68,9 +68,7 @@ pub enum ApplyExtensionCanisterTypesError {
 
 #[derive(Error, Debug)]
 pub enum ApplyExtensionCanisterTypeError {
-    #[error(
-        "failed to apply defaults from extension '{extension}' to canister '{canister}'"
-    )]
+    #[error("failed to apply defaults from extension '{extension}' to canister '{canister}'")]
     ApplyDefaults {
         canister: Box<String>,
         extension: Box<String>,