diff --git a/Library/Homebrew/service.rb b/Library/Homebrew/service.rb
index 1fba85547d..5b4245cde5 100644
--- a/Library/Homebrew/service.rb
+++ b/Library/Homebrew/service.rb
@@ -303,7 +303,7 @@ module Homebrew
       }
 
       base[:KeepAlive] = @keep_alive if @keep_alive == true
-      base[:LaunchOnlyOnce] = @launch_only_once if @launch_only_once == false
+      base[:LaunchOnlyOnce] = @launch_only_once if @launch_only_once == true
       base[:LegacyTimers] = @macos_legacy_timers if @macos_legacy_timers == true
       base[:TimeOut] = @restart_delay if @restart_delay.present?
       base[:ProcessType] = @process_type.to_s.capitalize if @process_type.present?
diff --git a/Library/Homebrew/test/service_spec.rb b/Library/Homebrew/test/service_spec.rb
index da1c8ec20d..b1d10b74a2 100644
--- a/Library/Homebrew/test/service_spec.rb
+++ b/Library/Homebrew/test/service_spec.rb
@@ -102,6 +102,7 @@ describe Homebrew::Service do
         root_dir var
         working_dir var
         keep_alive true
+        launch_only_once true
         process_type :interactive
         restart_delay 30
         interval 5
@@ -127,6 +128,8 @@ describe Homebrew::Service do
         \t<true/>
         \t<key>Label</key>
         \t<string>homebrew.mxcl.formula_name</string>
+        \t<key>LaunchOnlyOnce</key>
+        \t<true/>
         \t<key>LegacyTimers</key>
         \t<true/>
         \t<key>ProcessType</key>