diff --git a/lib/workers/repository/finalise/validate.js b/lib/workers/repository/finalise/validate.js
index ae124639b6..af3590340c 100644
--- a/lib/workers/repository/finalise/validate.js
+++ b/lib/workers/repository/finalise/validate.js
@@ -1,3 +1,4 @@
+const JSON5 = require('json5');
 const { migrateAndValidate } = require('../../../config/migrate-validate');
 const { configFileNames } = require('../../../config/app-strings');
 const { appName, appSlug } = require('../../../config/app-strings');
@@ -40,7 +41,12 @@ async function validatePrs(config) {
         }
         let parsed;
         try {
-          parsed = JSON.parse(content);
+          // istanbul ignore if
+          if (file.endsWith('.json5')) {
+            parsed = JSON5.parse(content);
+          } else {
+            parsed = JSON.parse(content);
+          }
         } catch (err) {
           validations.push({
             file,