diff --git a/lib/train/transports/mock.rb b/lib/train/transports/mock.rb
index 701b68f9..0fc7ed93 100644
--- a/lib/train/transports/mock.rb
+++ b/lib/train/transports/mock.rb
@@ -75,7 +75,9 @@ def mock_command(cmd, stdout = nil, stderr = nil, exit_status = 0)
     end
 
     def run_command(cmd)
-      @commands[cmd] || mock_command(cmd)
+      @commands[cmd] ||
+        @commands[Digest::SHA256.hexdigest cmd] ||
+        mock_command(cmd)
     end
 
     def file(path)
diff --git a/test/unit/transports/mock_test.rb b/test/unit/transports/mock_test.rb
index 5cadbf68..39bebb42 100644
--- a/test/unit/transports/mock_test.rb
+++ b/test/unit/transports/mock_test.rb
@@ -1,6 +1,7 @@
 # encoding: utf-8
 require 'helper'
 require 'train/transports/mock'
+require 'digest/sha2'
 
 describe 'mock transport' do
   let(:transport) { Train::Transports::Mock.new }
@@ -44,6 +45,14 @@
       connection.mock_command(cmd, nil, nil, code)
       connection.run_command(cmd).exit_status.must_equal(code)
     end
+
+    it 'can mock a command via its SHA2 sum' do
+      out = rand.to_s
+      cmd = rand.to_s
+      shacmd = Digest::SHA256.hexdigest cmd
+      connection.mock_command(shacmd, out)
+      connection.run_command(cmd).stdout.must_equal(out)
+    end
   end
 
   describe 'when accessing a mocked os' do