diff --git a/Library/Homebrew/extend/os/mac/caveats.rb b/Library/Homebrew/extend/os/mac/caveats.rb
index 2a3f8a8029..7abc7655ad 100644
--- a/Library/Homebrew/extend/os/mac/caveats.rb
+++ b/Library/Homebrew/extend/os/mac/caveats.rb
@@ -37,9 +37,14 @@ class Caveats
 
     if f.plist_manual || f.service?
       command = if f.service?
-        f.service.command
-         .map { |arg| (arg =~ /\s/) ? "'#{arg}'" : arg } # wrap multi-word arguments in quotes
-         .join(" ")
+        f.service
+         .command
+         .map do |arg|
+           next arg unless arg.match?(/\s/)
+
+           # quote multi-word arguments
+           "'#{arg}'"
+         end.join(" ")
       else
         f.plist_manual
       end