diff --git a/VimR/FileItemService.swift b/VimR/FileItemService.swift
index ecbbde3a..f71f68b8 100644
--- a/VimR/FileItemService.swift
+++ b/VimR/FileItemService.swift
@@ -105,7 +105,7 @@ class FileItemService: StandardFlow {
 
       // TODO Remove cached items more aggressively?
       let hasRelations = self.monitors.keys.reduce(false) { (result, monitoredUrl) in
-        return result ? result : monitoredUrl.parent(ofUrl: url) || url.parent(ofUrl: monitoredUrl)
+        return result ? result : monitoredUrl.isParent(of: url) || url.isParent(of: monitoredUrl)
       }
 
       if hasRelations {
diff --git a/VimR/FileOutlineView.swift b/VimR/FileOutlineView.swift
index b5ff1848..cc1460d4 100644
--- a/VimR/FileOutlineView.swift
+++ b/VimR/FileOutlineView.swift
@@ -62,7 +62,7 @@ extension FileOutlineView {
       self.fileItems.remove(fileItem)
       if fileItem.dir {
         self.fileItems
-          .filter { fileItem.url.parent(ofUrl: $0.url) }
+          .filter { fileItem.url.isParent(of: $0.url) }
           .forEach { self.fileItems.remove($0) }
       }
     }
diff --git a/VimR/FoundationCommons.swift b/VimR/FoundationCommons.swift
index 052deb94..ca3acb5d 100644
--- a/VimR/FoundationCommons.swift
+++ b/VimR/FoundationCommons.swift
@@ -7,7 +7,7 @@ import Foundation
 
 extension URL {
 
-  func parent(ofUrl url: URL) -> Bool {
+  func isParent(of url: URL) -> Bool {
     guard self.isFileURL && url.isFileURL else {
       return false
     }