diff --git a/lib/util/get-npmignore.js b/lib/util/get-npmignore.js
index 0e8699e6..9940e3f8 100644
--- a/lib/util/get-npmignore.js
+++ b/lib/util/get-npmignore.js
@@ -24,7 +24,7 @@ const NEVER_IGNORED = /^(?:readme\.[^.]*|(?:licen[cs]e|changes|changelog|history
  * @returns {boolean} `true` if the file name is a relative path to a ancestor
  *      directory.
  */
-function notAncestorFiles(filePath) {
+function isAncestorFiles(filePath) {
     return PARENT_RELATIVE_PATH.test(filePath)
 }
 
@@ -124,7 +124,7 @@ function parseNpmignore(basedir, filesFieldExists) {
 }
 
 /**
- * Gets an object to check whether or not a given path should be ignored.
+ * Gets an object to check whether a given path should be ignored or not.
  * The object is created from:
  *
  * - `files` field of `package.json`
@@ -137,7 +137,7 @@ function parseNpmignore(basedir, filesFieldExists) {
  *      `match` returns `true` if a given file path should be ignored.
  */
 module.exports = function getNpmignore(startPath) {
-    const retv = { match: notAncestorFiles }
+    const retv = { match: isAncestorFiles }
 
     const p = getPackageJson(startPath)
     if (p) {
@@ -155,17 +155,17 @@ module.exports = function getNpmignore(startPath) {
         if (filesIgnore && npmignoreIgnore) {
             retv.match = and(
                 filterNeverIgnoredFiles(p),
-                or(notAncestorFiles, filesIgnore, npmignoreIgnore)
+                or(isAncestorFiles, filesIgnore, npmignoreIgnore)
             )
         } else if (filesIgnore) {
             retv.match = and(
                 filterNeverIgnoredFiles(p),
-                or(notAncestorFiles, filesIgnore)
+                or(isAncestorFiles, filesIgnore)
             )
         } else if (npmignoreIgnore) {
             retv.match = and(
                 filterNeverIgnoredFiles(p),
-                or(notAncestorFiles, npmignoreIgnore)
+                or(isAncestorFiles, npmignoreIgnore)
             )
         }