diff --git a/Union-Find/UnionFind.playground/Contents.swift b/Union-Find/UnionFind.playground/Contents.swift
index 6ac3b4c4e..b1f7fb4e1 100644
--- a/Union-Find/UnionFind.playground/Contents.swift
+++ b/Union-Find/UnionFind.playground/Contents.swift
@@ -1,10 +1,5 @@
 //: Playground - noun: a place where people can play
 
-// last checked with Xcode 9.0b4
-#if swift(>=4.0)
-print("Hello, Swift 4!")
-#endif
-
 var dsu = UnionFindQuickUnion<Int>()
 
 for i in 1...10 {
diff --git a/Union-Find/UnionFind.playground/playground.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist b/Union-Find/UnionFind.playground/playground.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
new file mode 100644
index 000000000..18d981003
--- /dev/null
+++ b/Union-Find/UnionFind.playground/playground.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist
@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>