diff --git a/Library/Homebrew/extend/os/mac/caveats.rb b/Library/Homebrew/extend/os/mac/caveats.rb
index 6f9bc6639c..7abc7655ad 100644
--- a/Library/Homebrew/extend/os/mac/caveats.rb
+++ b/Library/Homebrew/extend/os/mac/caveats.rb
@@ -37,7 +37,14 @@ class Caveats
 
     if f.plist_manual || f.service?
       command = if f.service?
-        f.service.command.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
diff --git a/Library/Homebrew/test/caveats_spec.rb b/Library/Homebrew/test/caveats_spec.rb
index f6d76521ac..571e471016 100644
--- a/Library/Homebrew/test/caveats_spec.rb
+++ b/Library/Homebrew/test/caveats_spec.rb
@@ -128,6 +128,20 @@ describe Caveats do
         expect(caveats).to include("background service")
       end
 
+      it "wraps multi-word service parameters" do
+        f = formula do
+          url "foo-1.0"
+          service do
+            run [bin/"nginx", "-g", "daemon off;"]
+          end
+        end
+        caveats = described_class.new(f).caveats
+
+        expect(f.service?).to eq(true)
+        expect(caveats).to include("#{f.bin}/nginx -g 'daemon off;'")
+        expect(caveats).to include("background service")
+      end
+
       it "warns about brew failing under tmux" do
         f = formula do
           url "foo-1.0"