diff --git a/packages/gatsby/package.json b/packages/gatsby/package.json
index 5a739fcef98e5..e3c578ab72fca 100644
--- a/packages/gatsby/package.json
+++ b/packages/gatsby/package.json
@@ -44,7 +44,7 @@
     "express-graphql": "^0.6.6",
     "fast-levenshtein": "~2.0.4",
     "file-loader": "^0.9.0",
-    "flat": "^2.0.1",
+    "flat": "^5.0.2",
     "friendly-errors-webpack-plugin": "^1.6.1",
     "front-matter": "^2.1.0",
     "fs-extra": "^4.0.1",