diff --git a/Rakefile b/Rakefile
index 1382a5afa..7679fa4bc 100644
--- a/Rakefile
+++ b/Rakefile
@@ -53,6 +53,7 @@ require_relative "rake.d/library"
 require_relative "rake.d/format_string_verifier"
 require_relative "rake.d/pch"
 require_relative "rake.d/po"
+require_relative "rake.d/source_tests"
 require_relative "rake.d/tarball"
 require_relative 'rake.d/gtest' if $have_gtest
 
@@ -857,6 +858,11 @@ namespace :tests do
   task :products do
     run "cd tests && ./run.rb"
   end
+
+  desc "Run built-in tests on source code files"
+  task :source do
+    Mtx::SourceTests.test_include_guards
+  end
 end
 
 #
diff --git a/rake.d/source_tests.rb b/rake.d/source_tests.rb
new file mode 100644
index 000000000..9825a2179
--- /dev/null
+++ b/rake.d/source_tests.rb
@@ -0,0 +1,69 @@
+# coding: utf-8
+
+module Mtx::SourceTests
+  def self.collect_header_files
+    ui_file_names        = FileList["src/**/*.ui"]
+    ui_header_file_names = ui_file_names.collect { |file_name| file_name.ext 'h' }.to_a
+    header_file_names    = FileList["src/**/*.h"].to_a.sort
+
+    header_file_names - ui_header_file_names
+  end
+
+  def self.expected_guard_name file_name
+    "MTX_" + file_name.
+      gsub(%r{.*src/}, '').
+      gsub(%r{[/.]}, '_').
+      upcase
+  end
+
+  def self.test_include_guard_for_file file_name, lines
+    guard_line_idx = (0...lines.size).select { |idx| %r{^#ifndef +MTX_}.match(lines[idx]) }[0]
+
+    if !guard_line_idx
+      puts "#{file_name}:1: error: no include guard line found"
+      return false
+    end
+
+    ok            = true
+    guard_line    = lines[guard_line_idx].chomp
+    guard_name    = guard_line.gsub(%r{^#ifndef +}, '').gsub(%r{ .*}, '')
+    expected_name = self.expected_guard_name file_name
+
+    if guard_name != expected_name
+      puts "#{file_name}:#{guard_line_idx + 1}: error: wrong guard name: #{guard_name}; should be: #{expected_name}"
+      ok = false
+    end
+
+    guard_def_line    = lines[guard_line_idx + 1].chomp
+    expected_def_line = "#define #{expected_name}"
+
+    if guard_def_line != expected_def_line
+      puts "#{file_name}:#{guard_line_idx + 2}: error: guard definition line wrong or not found; should be: #{expected_def_line}"
+      ok = false
+    end
+
+    guard_end_line  = lines.last
+    expected_end_re = "^\\#endif \\s+ // \\s+ #{expected_name} $"
+
+    if !%r(#{expected_end_re})x.match(guard_end_line)
+      puts "#{file_name}:#{lines.size}: error: guard end line wrong or not found; should match RE: #{expected_end_re}"
+      ok = false
+    end
+
+    ok
+  end
+
+  def self.test_include_guards
+    file_names = self.collect_header_files
+    content    = read_files file_names
+    ok         = true
+
+    file_names.each do |file_name|
+      if !self.test_include_guard_for_file(file_name, content[file_name])
+        ok = false
+      end
+    end
+
+    exit 1 if !ok
+  end
+end