diff --git a/core/server/lib/fs/package-json/index.js b/core/server/lib/fs/package-json/index.js
index 3f50a1a568..89b8232e17 100644
--- a/core/server/lib/fs/package-json/index.js
+++ b/core/server/lib/fs/package-json/index.js
@@ -1,4 +1,4 @@
 const PackageJson = require('./package-json');
 const {i18n} = require('../../common');
 
-module.exports = new PackageJson(i18n);
+module.exports = new PackageJson({i18n});
diff --git a/core/server/lib/fs/package-json/package-json.js b/core/server/lib/fs/package-json/package-json.js
index 0e9628be01..e5b8d46e38 100644
--- a/core/server/lib/fs/package-json/package-json.js
+++ b/core/server/lib/fs/package-json/package-json.js
@@ -7,6 +7,11 @@ const errors = require('@tryghost/errors');
 const notAPackageRegex = /^\.|_messages|README.md|node_modules|bower_components/i;
 const packageJSONPath = 'package.json';
 
+/**
+ * @typedef {Object} Ii18n
+ * @prop {(key: string) => string} t
+ */
+
 /**
  * # Package Utils
  *
@@ -15,9 +20,15 @@ const packageJSONPath = 'package.json';
  * - Adapters: replace fundamental pieces like storage, will become npm modules
  *
  * These utils facilitate loading, reading, managing etc, packages from the file system.
+ * 
  */
 module.exports = class PackageJson {
-    constructor(i18n) {
+    /**
+     * Creates an instance of PackageJson, an util used to read and validate package.json files
+     * @param {Object} dependencies
+     * @param {Ii18n} dependencies.i18n
+     */
+    constructor({i18n}) {
         this.i18n = i18n;
     }
 
diff --git a/test/unit/lib/fs/package-json/filter_spec.js b/test/unit/lib/fs/package-json/filter_spec.js
index d3b1709a56..854f810708 100644
--- a/test/unit/lib/fs/package-json/filter_spec.js
+++ b/test/unit/lib/fs/package-json/filter_spec.js
@@ -1,5 +1,11 @@
 const should = require('should');
-const packageJSON = require('../../../../../core/server/lib/fs/package-json');
+const PackageJSON = require('../../../../../core/server/lib/fs/package-json/package-json');
+
+const packageJSON = new PackageJSON({
+    i18n: {
+        t: key => key
+    }
+});
 
 describe('lib/fs/package-json', function () {
     // @TODO: introduce some non-theme package examples
diff --git a/test/unit/lib/fs/package-json/parse_spec.js b/test/unit/lib/fs/package-json/parse_spec.js
index 0de6ff8478..ffe3b206ac 100644
--- a/test/unit/lib/fs/package-json/parse_spec.js
+++ b/test/unit/lib/fs/package-json/parse_spec.js
@@ -1,7 +1,13 @@
 const should = require('should');
 const tmp = require('tmp');
 const fs = require('fs-extra');
-const packageJSON = require('../../../../../core/server/lib/fs/package-json');
+const PackageJSON = require('../../../../../core/server/lib/fs/package-json/package-json');
+
+const packageJSON = new PackageJSON({
+    i18n: {
+        t: key => key
+    }
+});
 
 describe('lib/fs/package-json: parse', function () {
     it('should parse valid package.json', function (done) {
@@ -45,9 +51,9 @@ describe('lib/fs/package-json: parse', function () {
                 done(new Error('packageJSON.parse succeeded, but should\'ve failed'));
             })
             .catch(function (err) {
-                err.message.should.equal('"name" or "version" is missing from theme package.json file.');
+                err.message.should.equal('errors.utils.parsepackagejson.nameOrVersionMissing');
                 err.context.should.equal(tmpFile.name);
-                err.help.should.equal('This will be required in future. Please see https://ghost.org/docs/api/handlebars-themes/');
+                err.help.should.equal('errors.utils.parsepackagejson.willBeRequired');
 
                 done();
             })
@@ -71,9 +77,9 @@ describe('lib/fs/package-json: parse', function () {
                 done(new Error('packageJSON.parse succeeded, but should\'ve failed'));
             })
             .catch(function (err) {
-                err.message.should.equal('"name" or "version" is missing from theme package.json file.');
+                err.message.should.equal('errors.utils.parsepackagejson.nameOrVersionMissing');
                 err.context.should.equal(tmpFile.name);
-                err.help.should.equal('This will be required in future. Please see https://ghost.org/docs/api/handlebars-themes/');
+                err.help.should.equal('errors.utils.parsepackagejson.willBeRequired');
 
                 done();
             })
@@ -95,9 +101,9 @@ describe('lib/fs/package-json: parse', function () {
                 done(new Error('packageJSON.parse succeeded, but should\'ve failed'));
             })
             .catch(function (err) {
-                err.message.should.equal('Theme package.json file is malformed');
+                err.message.should.equal('errors.utils.parsepackagejson.themeFileIsMalformed');
                 err.context.should.equal(tmpFile.name);
-                err.help.should.equal('This will be required in future. Please see https://ghost.org/docs/api/handlebars-themes/');
+                err.help.should.equal('errors.utils.parsepackagejson.willBeRequired');
 
                 done();
             })
@@ -114,7 +120,7 @@ describe('lib/fs/package-json: parse', function () {
                 done(new Error('packageJSON.parse succeeded, but should\'ve failed'));
             })
             .catch(function (err) {
-                err.message.should.equal('Could not read package.json file');
+                err.message.should.equal('errors.utils.parsepackagejson.couldNotReadPackage');
                 err.context.should.equal(tmpFile.name);
 
                 done();
diff --git a/test/unit/lib/fs/package-json/read_spec.js b/test/unit/lib/fs/package-json/read_spec.js
index 7fb29c8aee..2f2a83ce06 100644
--- a/test/unit/lib/fs/package-json/read_spec.js
+++ b/test/unit/lib/fs/package-json/read_spec.js
@@ -2,7 +2,13 @@ const should = require('should');
 const tmp = require('tmp');
 const join = require('path').join;
 const fs = require('fs-extra');
-const packageJSON = require('../../../../../core/server/lib/fs/package-json');
+const PackageJSON = require('../../../../../core/server/lib/fs/package-json/package-json');
+
+const packageJSON = new PackageJSON({
+    i18n: {
+        t: key => key
+    }
+});
 
 describe('lib/fs/package-json: read', function () {
     describe('all', function () {