diff --git a/lib/jekyll-compose.rb b/lib/jekyll-compose.rb
index 92f34ec..b492052 100644
--- a/lib/jekyll-compose.rb
+++ b/lib/jekyll-compose.rb
@@ -2,6 +2,8 @@
 
 module Jekyll
   module Compose
+    DEFAULT_TYPE = "md"
+    DEFAULT_LAYOUT = "post"
   end
 end
 
diff --git a/lib/jekyll/commands/draft.rb b/lib/jekyll/commands/draft.rb
index 2bd0be9..7272f42 100644
--- a/lib/jekyll/commands/draft.rb
+++ b/lib/jekyll/commands/draft.rb
@@ -19,8 +19,8 @@ def self.init_with_program(prog)
       def self.process(args = [], options = {})
         raise ArgumentError.new('You must specify a name.') if args.empty?
 
-        type = options["type"] || "markdown"
-        layout = options["layout"] || "post"
+        type = options["type"] || Jekyll::Compose::DEFAULT_TYPE
+        layout = options["layout"] || Jekyll::Compose::DEFAULT_LAYOUT
 
         title = args.shift
         name = title.gsub(' ', '-').downcase
@@ -38,7 +38,7 @@ def self.process(args = [], options = {})
       # Internal: Gets the filename of the draft to be created
       #
       # Returns the filename of the draft, as a String
-      def self.draft_name(name, ext='markdown')
+      def self.draft_name(name, ext=Jekyll::Compose::DEFAULT_TYPE)
         "_drafts/#{name}.#{ext}"
       end
 
diff --git a/lib/jekyll/commands/post.rb b/lib/jekyll/commands/post.rb
index da35d02..6b939d6 100644
--- a/lib/jekyll/commands/post.rb
+++ b/lib/jekyll/commands/post.rb
@@ -20,8 +20,8 @@ def self.init_with_program(prog)
       def self.process(args = [], options = {})
         raise ArgumentError.new('You must specify a name.') if args.empty?
 
-        type = options["type"].nil? ? "markdown" : options["type"]
-        layout = options["layout"].nil? ? "post" : options["layout"]
+        type = options["type"] || Jekyll::Compose::DEFAULT_TYPE
+        layout = options["layout"] || Jekyll::Compose::DEFAULT_LAYOUT
 
         date = options["date"].nil? ? Time.now : DateTime.parse(options["date"])
 
diff --git a/spec/draft_spec.rb b/spec/draft_spec.rb
index 0d03d73..2556342 100644
--- a/spec/draft_spec.rb
+++ b/spec/draft_spec.rb
@@ -2,7 +2,7 @@
   let(:name) { 'A test post' }
   let(:args) { [name] }
   let(:drafts_dir) { Pathname.new source_dir('_drafts') }
-  let(:path) { drafts_dir.join('a-test-post.markdown') }
+  let(:path) { drafts_dir.join('a-test-post.md') }
 
   before(:all) do
     FileUtils.mkdir_p source_dir unless File.directory? source_dir
@@ -25,7 +25,7 @@
 
   it 'writes a helpful success message' do
     output = capture_stdout { described_class.process(args) }
-    expect(output).to eql("New draft created at ./_drafts/a-test-post.markdown.\n")
+    expect(output).to eql("New draft created at ./_drafts/a-test-post.md.\n")
   end
 
   it 'errors with no arguments' do
@@ -36,7 +36,7 @@
 
   context 'when the draft already exists' do
     let(:name) { 'An existing draft' }
-    let(:path) { drafts_dir.join('an-existing-draft.markdown') }
+    let(:path) { drafts_dir.join('an-existing-draft.md') }
 
     before(:each) do
       FileUtils.touch path
@@ -45,7 +45,7 @@
     it 'raises an error' do
       expect(-> {
         capture_stdout { described_class.process(args) }
-      }).to raise_error("A draft already exists at ./_drafts/an-existing-draft.markdown")
+      }).to raise_error("A draft already exists at ./_drafts/an-existing-draft.md")
     end
 
     it 'overwrites if --force is given' do
diff --git a/spec/post_spec.rb b/spec/post_spec.rb
index e9b27a5..d94485a 100644
--- a/spec/post_spec.rb
+++ b/spec/post_spec.rb
@@ -2,7 +2,7 @@
   let(:name) { 'A test post' }
   let(:args) { [name] }
   let(:posts_dir) { Pathname.new source_dir('_posts') }
-  let(:filename) { "#{Time.now.strftime('%Y-%m-%d')}-a-test-post.markdown" }
+  let(:filename) { "#{Time.now.strftime('%Y-%m-%d')}-a-test-post.md" }
   let(:path) { posts_dir.join(filename) }
 
   before(:all) do
@@ -37,7 +37,7 @@
 
   context 'when the post already exists' do
     let(:name) { 'An existing post' }
-    let(:filename) { "#{Time.now.strftime('%Y-%m-%d')}-an-existing-post.markdown" }
+    let(:filename) { "#{Time.now.strftime('%Y-%m-%d')}-an-existing-post.md" }
 
     before(:each) do
       FileUtils.touch path