diff --git a/Formula/graphite.rb b/Formula/graphite.rb
index fbcd8df..7d78764 100644
--- a/Formula/graphite.rb
+++ b/Formula/graphite.rb
@@ -6,17 +6,23 @@ class Graphite < Formula
   if OS.mac?
     url "https://github.com/withgraphite/homebrew-tap/releases/download/v0.21.0/gt-macos"
     sha256 "b498330dbfea3810ec0822d4d106f69fe8182c9a0eefbb8b9b794500c22cc573"
-    def install
-      bin.install "gt-macos" => "gt"
-    end
   end
 
   if OS.linux?
     url "https://github.com/withgraphite/homebrew-tap/releases/download/v0.21.0/gt-linux"
     sha256 "ea22d355da93c59300ee83ac9ef58d63126c41a80d9a39076a5de9420ae789d9"
-    def install
+  end
+
+  def install
+    if OS.mac?
+      bin.install "gt-macos" => "gt"
+    elsif OS.linux?
       bin.install "gt-linux" => "gt"
     end
+
+    chmod 0555, bin/"gt"
+    generate_completions_from_executable(bin/"gt", "completion", shells:                 [:bash, :zsh, :fish],
+                                                                 shell_parameter_format: :none)
   end
 
   # TODO
diff --git a/formula-templates/graphite.rb b/formula-templates/graphite.rb
index cb01112..cc55fc4 100644
--- a/formula-templates/graphite.rb
+++ b/formula-templates/graphite.rb
@@ -6,17 +6,23 @@ class Graphite < Formula
   if OS.mac?
     url "{{urlMac}}"
     sha256 "{{shasumMac}}"
-    def install
-      bin.install "gt-macos" => "gt"
-    end
   end
 
   if OS.linux?
     url "{{urlLinux}}"
     sha256 "{{shasumLinux}}"
-    def install
+  end
+
+  def install
+    if OS.mac?
+      bin.install "gt-macos" => "gt"
+    elsif OS.linux?
       bin.install "gt-linux" => "gt"
     end
+
+    chmod 0555, bin/"gt"
+    generate_completions_from_executable(bin/"gt", "completion", shells:                 [:bash, :zsh, :fish],
+                                                                 shell_parameter_format: :none)
   end
 
   # TODO