diff --git a/file.js b/file.js
index e824b9e36..7968c1945 100644
--- a/file.js
+++ b/file.js
@@ -4,15 +4,7 @@ const pino = require('./pino')
 const { once } = require('events')
 
 module.exports = async function (opts = {}) {
-  const destination = pino.destination({ dest: normalizeDest(opts.destination || 1), sync: false })
+  const destination = pino.destination({ dest: opts.destination || 1, sync: false })
   await once(destination, 'ready')
   return destination
 }
-
-function normalizeDest (destination) {
-  const fd = Number(destination)
-  if (typeof destination === 'string' && Number.isFinite(fd)) {
-    return fd
-  }
-  return destination
-}
diff --git a/lib/tools.js b/lib/tools.js
index 8532c8c86..14cce4844 100644
--- a/lib/tools.js
+++ b/lib/tools.js
@@ -514,6 +514,22 @@ function setMetadataProps (dest, that) {
   }
 }
 
+/**
+ * Convert a string integer file descriptor to a proper native integer
+ * file descriptor.
+ *
+ * @param {string} destination The file descriptor string to attempt to convert.
+ *
+ * @returns {Number}
+ */
+function normalizeDestFileDescriptor (destination) {
+  const fd = Number(destination)
+  if (typeof destination === 'string' && Number.isFinite(fd)) {
+    return fd
+  }
+  return destination
+}
+
 module.exports = {
   noop,
   buildSafeSonicBoom,
@@ -524,5 +540,6 @@ module.exports = {
   createArgsNormalizer,
   final,
   stringify,
-  buildFormatters
+  buildFormatters,
+  normalizeDestFileDescriptor
 }
diff --git a/pino.js b/pino.js
index 980732281..31330c9c3 100644
--- a/pino.js
+++ b/pino.js
@@ -15,6 +15,7 @@ const {
   stringify,
   buildSafeSonicBoom,
   buildFormatters,
+  normalizeDestFileDescriptor,
   noop
 } = require('./lib/tools')
 const { version } = require('./lib/meta')
@@ -175,10 +176,10 @@ module.exports = pino
 
 module.exports.destination = (dest = process.stdout.fd) => {
   if (typeof dest === 'object') {
-    dest.dest = dest.dest || process.stdout.fd
+    dest.dest = normalizeDestFileDescriptor(dest.dest || process.stdout.fd)
     return buildSafeSonicBoom(dest)
   } else {
-    return buildSafeSonicBoom({ dest, minLength: 0, sync: true })
+    return buildSafeSonicBoom({ dest: normalizeDestFileDescriptor(dest), minLength: 0, sync: true })
   }
 }