diff --git a/browser/brave_wallet/external_wallets_importer.cc b/browser/brave_wallet/external_wallets_importer.cc
index 85187e09e1b..25ff164c272 100644
--- a/browser/brave_wallet/external_wallets_importer.cc
+++ b/browser/brave_wallet/external_wallets_importer.cc
@@ -226,7 +226,7 @@ void ExternalWalletsImporter::GetLocalStorage(
     const extensions::Extension& extension,
     InitCallback callback) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  std::string error;
+  std::u16string error;
   extension_ = Extension::Create(
       extension.path(), ManifestLocation::kExternalPref,
       *extension.manifest()->value(), extension.creation_flags(), &error);
diff --git a/browser/extensions/mv2_warning_unittest.cc b/browser/extensions/mv2_warning_unittest.cc
index 595046fb4bb..8e90abe133f 100644
--- a/browser/extensions/mv2_warning_unittest.cc
+++ b/browser/extensions/mv2_warning_unittest.cc
@@ -32,7 +32,7 @@ TEST(Mv2WarningTest, ExtensionManifestVersions) {
     return dict;
   };
 
-  std::string error;
+  std::u16string error;
   scoped_refptr<extensions::Extension> extension =
       extensions::Extension::Create(
           base::FilePath(), extensions::mojom::ManifestLocation::kUnpacked,