diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 623f44d56a6e6..606d5f2a5327e 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Update `rake stats` to  correctly count declarative tests
+    as methods in `_test.rb` files.
+
+    *Ravil Bayramgalin*
+
 *   Remove deprecated `test:all` and `test:all:db` tasks.
 
     *Rafael Mendonça França*
diff --git a/railties/lib/rails/code_statistics_calculator.rb b/railties/lib/rails/code_statistics_calculator.rb
index 60e4aef9b78fe..a142236dbed19 100644
--- a/railties/lib/rails/code_statistics_calculator.rb
+++ b/railties/lib/rails/code_statistics_calculator.rb
@@ -24,6 +24,8 @@ class CodeStatisticsCalculator #:nodoc:
     }
   }
 
+  PATTERNS[:minitest] = PATTERNS[:rb].merge method: /^\s*(def|test)\s+['"_a-z]/
+
   def initialize(lines = 0, code_lines = 0, classes = 0, methods = 0)
     @lines = lines
     @code_lines = code_lines
@@ -74,6 +76,10 @@ def add_by_io(io, file_type)
 
   private
     def file_type(file_path)
-      File.extname(file_path).sub(/\A\./, '').downcase.to_sym
+      if file_path.end_with? '_test.rb'
+        :minitest
+      else
+        File.extname(file_path).sub(/\A\./, '').downcase.to_sym
+      end
     end
 end
diff --git a/railties/test/code_statistics_calculator_test.rb b/railties/test/code_statistics_calculator_test.rb
index b3eabf5024015..46445a001ad62 100644
--- a/railties/test/code_statistics_calculator_test.rb
+++ b/railties/test/code_statistics_calculator_test.rb
@@ -6,6 +6,43 @@ def setup
     @code_statistics_calculator = CodeStatisticsCalculator.new
   end
 
+  test 'calculate statistics using #add_by_file_path' do
+    code = <<-RUBY
+      def foo
+        puts 'foo'
+        # bar
+      end
+    RUBY
+
+    temp_file 'stats.rb', code do |path|
+      @code_statistics_calculator.add_by_file_path path
+
+      assert_equal 4, @code_statistics_calculator.lines
+      assert_equal 3, @code_statistics_calculator.code_lines
+      assert_equal 0, @code_statistics_calculator.classes
+      assert_equal 1, @code_statistics_calculator.methods
+    end
+  end
+
+  test 'count number of methods in MiniTest file' do
+    code = <<-RUBY
+      class FooTest < ActionController::TestCase
+        test 'expectation' do
+          assert true
+        end
+
+        def test_expectation
+          assert true
+        end
+      end
+    RUBY
+
+    temp_file 'foo_test.rb', code do |path|
+      @code_statistics_calculator.add_by_file_path path
+      assert_equal 2, @code_statistics_calculator.methods
+    end
+  end
+
   test 'add statistics to another using #add' do
     code_statistics_calculator_1 = CodeStatisticsCalculator.new(1, 2, 3, 4)
     @code_statistics_calculator.add(code_statistics_calculator_1)
@@ -45,30 +82,6 @@ class A; end
     assert_equal 6, @code_statistics_calculator.methods
   end
 
-  test 'calculate statistics using #add_by_file_path' do
-    tmp_path = File.expand_path(File.join(File.dirname(__FILE__), 'fixtures', 'tmp'))
-    FileUtils.mkdir_p(tmp_path)
-
-    code = <<-'CODE'
-      def foo
-        puts 'foo'
-        # bar
-      end
-    CODE
-
-    file_path = "#{tmp_path}/stats.rb"
-    File.open(file_path, 'w') { |f| f.write(code) }
-
-    @code_statistics_calculator.add_by_file_path(file_path)
-
-    assert_equal 4, @code_statistics_calculator.lines
-    assert_equal 3, @code_statistics_calculator.code_lines
-    assert_equal 0, @code_statistics_calculator.classes
-    assert_equal 1, @code_statistics_calculator.methods
-
-    FileUtils.rm_rf(tmp_path)
-  end
-
   test 'calculate number of Ruby methods' do
     code = <<-'CODE'
       def foo
@@ -285,4 +298,17 @@ class Animal
     assert_equal 0, @code_statistics_calculator.classes
     assert_equal 0, @code_statistics_calculator.methods
   end
+
+  private
+    def temp_file(name, content)
+      dir = File.expand_path '../fixtures/tmp', __FILE__
+      path = "#{dir}/#{name}"
+
+      FileUtils.mkdir_p dir
+      File.write path, content
+
+      yield path
+    ensure
+      FileUtils.rm_rf path
+    end
 end