diff --git a/src/_read.cjs b/src/_read.cjs
index 27ad91b..70690a5 100644
--- a/src/_read.cjs
+++ b/src/_read.cjs
@@ -38,7 +38,7 @@ module.exports = async function read ({ scope = 'apps', token, appID, envID, pat
       // tiny 7 reads do NOT parse JSON errors; see tiny#37
       const { error, errors } = JSON.parse(err.body)
       if (error) throw Error(error)
-      if (errors) throw Error(Array.isArray(errors) ? errors.at(-1) : errors)
+      if (errors) throw Error(Array.isArray(errors) ? errors[errors.length - 1] : errors)
       else throw Error('unknown_error')
     }
     else {
diff --git a/src/_write.cjs b/src/_write.cjs
index 2e1e49f..2b44c60 100644
--- a/src/_write.cjs
+++ b/src/_write.cjs
@@ -39,7 +39,7 @@ module.exports = async function write ({ scope = 'apps', token, _staging, appID,
       // tiny 7 writes DO parse JSON errors; see tiny#37
       const { error, errors } = err.body
       if (error) throw Error(error)
-      if (errors) throw Error(Array.isArray(errors) ? errors.at(-1) : errors)
+      if (errors) throw Error(Array.isArray(errors) ? errors[errors.length - 1] : errors)
       else throw Error('unknown_error')
     }
     else {