diff --git a/tools/validate-file-refs.js b/tools/validate-file-refs.js
index 75a802967..b1261a4d7 100644
--- a/tools/validate-file-refs.js
+++ b/tools/validate-file-refs.js
@@ -80,7 +80,7 @@ function escapeTableCell(str) {
 }
 
 // Path prefixes/patterns that only exist in installed structure, not in source
-const INSTALL_ONLY_PATHS = ['_config/'];
+const INSTALL_ONLY_PATHS = ['_config/', 'customizations/'];
 
 // Files that are generated at install time and don't exist in the source tree
 const INSTALL_GENERATED_FILES = ['config.yaml', 'config.user.yaml'];