diff --git a/Library/Homebrew/mktemp.rb b/Library/Homebrew/mktemp.rb
index e7b50a9740..0127327189 100644
--- a/Library/Homebrew/mktemp.rb
+++ b/Library/Homebrew/mktemp.rb
@@ -47,11 +47,11 @@ class Mktemp
 
   def run
     prefix_name = @prefix.tr "@", "AT"
-    if @retain_in_cache
+    if retain_in_cache?
       source_dir = "#{HOMEBREW_CACHE}/Sources/#{prefix_name}"
-      chmod_rm_rf(source_dir) # clear out previous (otherwise not sure what happens)
-      FileUtils.mkdir_p(source_dir)
       @tmpdir = Pathname.new(source_dir)
+      chmod_rm_rf(@tmpdir) # clear out previous (otherwise not sure what happens)
+      FileUtils.mkdir_p(source_dir)
     else
       @tmpdir = Pathname.new(Dir.mktmpdir("#{prefix_name}-", HOMEBREW_TEMP))
     end