diff --git a/doc/api/modules.md b/doc/api/modules.md
index 326a4cc4b45254..dc302c1990b77f 100644
--- a/doc/api/modules.md
+++ b/doc/api/modules.md
@@ -626,9 +626,11 @@ added: v8.9.0
 -->
 
 * `request` {string} The module path whose lookup paths are being retrieved.
-* Returns: {Array}
+* Returns: {Array|null}
 
-Returns an array containing the paths searched during resolution of `request`.
+Returns an array containing the paths searched during resolution of `request` or
+null if the `request` string references a core module, for example `http` or
+`fs`.
 
 ## The `module` Object
 <!-- YAML