diff --git a/toml/color.hpp b/toml/color.hpp
index d85a848..4cb572c 100644
--- a/toml/color.hpp
+++ b/toml/color.hpp
@@ -1,7 +1,7 @@
 #ifndef TOML11_COLOR_HPP
 #define TOML11_COLOR_HPP
-#include <ostream>
 #include <cstdint>
+#include <ostream>
 
 #ifdef TOML11_COLORIZE_ERROR_MESSAGE
 #define TOML11_ERROR_MESSAGE_COLORIZED true
diff --git a/toml/combinator.hpp b/toml/combinator.hpp
index aa82012..3d72718 100644
--- a/toml/combinator.hpp
+++ b/toml/combinator.hpp
@@ -2,18 +2,20 @@
 // Distributed under the MIT License.
 #ifndef TOML11_COMBINATOR_HPP
 #define TOML11_COMBINATOR_HPP
-#include "traits.hpp"
-#include "result.hpp"
-#include "utility.hpp"
-#include "region.hpp"
-#include <type_traits>
-#include <iterator>
-#include <limits>
-#include <array>
-#include <iomanip>
-#include <cstdio>
 #include <cassert>
 #include <cctype>
+#include <cstdio>
+
+#include <array>
+#include <iomanip>
+#include <iterator>
+#include <limits>
+#include <type_traits>
+
+#include "region.hpp"
+#include "result.hpp"
+#include "traits.hpp"
+#include "utility.hpp"
 
 // they scans characters and returns region if it matches to the condition.
 // when they fail, it does not change the location.
diff --git a/toml/comments.hpp b/toml/comments.hpp
index 9cf1ad4..1e17544 100644
--- a/toml/comments.hpp
+++ b/toml/comments.hpp
@@ -2,12 +2,12 @@
 // Distributed under the MIT License.
 #ifndef TOML11_COMMENTS_HPP
 #define TOML11_COMMENTS_HPP
+#include <initializer_list>
+#include <iterator>
+#include <string>
 #include <type_traits>
 #include <utility>
-#include <iterator>
-#include <initializer_list>
 #include <vector>
-#include <string>
 
 // This file provides mainly two classes, `preserve_comments` and `discard_comments`.
 // Those two are a container that have the same interface as `std::vector<std::string>`
diff --git a/toml/datetime.hpp b/toml/datetime.hpp
index 3fdec44..d8127c1 100644
--- a/toml/datetime.hpp
+++ b/toml/datetime.hpp
@@ -2,15 +2,16 @@
 // Distributed under the MIT License.
 #ifndef TOML11_DATETIME_HPP
 #define TOML11_DATETIME_HPP
-#include <chrono>
-#include <tuple>
-#include <array>
-#include <ostream>
-#include <iomanip>
 #include <cstdint>
 #include <cstdlib>
 #include <ctime>
 
+#include <array>
+#include <chrono>
+#include <iomanip>
+#include <ostream>
+#include <tuple>
+
 namespace toml
 {
 
diff --git a/toml/exception.hpp b/toml/exception.hpp
index 42ae3b1..c64651d 100644
--- a/toml/exception.hpp
+++ b/toml/exception.hpp
@@ -2,10 +2,11 @@
 // Distributed under the MIT License.
 #ifndef TOML11_EXCEPTION_HPP
 #define TOML11_EXCEPTION_HPP
-#include "source_location.hpp"
 #include <stdexcept>
 #include <string>
 
+#include "source_location.hpp"
+
 namespace toml
 {
 
diff --git a/toml/get.hpp b/toml/get.hpp
index c7fef32..93b834a 100644
--- a/toml/get.hpp
+++ b/toml/get.hpp
@@ -2,10 +2,11 @@
 // Distributed under the MIT License.
 #ifndef TOML11_GET_HPP
 #define TOML11_GET_HPP
+#include <algorithm>
+
 #include "from.hpp"
 #include "result.hpp"
 #include "value.hpp"
-#include <algorithm>
 
 namespace toml
 {
diff --git a/toml/lexer.hpp b/toml/lexer.hpp
index ee672c1..2eea996 100644
--- a/toml/lexer.hpp
+++ b/toml/lexer.hpp
@@ -2,12 +2,13 @@
 // Distributed under the MIT License.
 #ifndef TOML11_LEXER_HPP
 #define TOML11_LEXER_HPP
-#include "combinator.hpp"
-#include <stdexcept>
 #include <istream>
 #include <sstream>
+#include <stdexcept>
 #include <fstream>
 
+#include "combinator.hpp"
+
 namespace toml
 {
 namespace detail
diff --git a/toml/parser.hpp b/toml/parser.hpp
index 966f8a1..589add9 100644
--- a/toml/parser.hpp
+++ b/toml/parser.hpp
@@ -2,15 +2,16 @@
 // Distributed under the MIT License.
 #ifndef TOML11_PARSER_HPP
 #define TOML11_PARSER_HPP
-#include "result.hpp"
-#include "region.hpp"
-#include "combinator.hpp"
-#include "lexer.hpp"
-#include "types.hpp"
-#include "value.hpp"
+#include <cstring>
 #include <fstream>
 #include <sstream>
-#include <cstring>
+
+#include "combinator.hpp"
+#include "lexer.hpp"
+#include "region.hpp"
+#include "result.hpp"
+#include "types.hpp"
+#include "value.hpp"
 
 #if __cplusplus >= 201703L
 #if __has_include(<filesystem>)
diff --git a/toml/serializer.hpp b/toml/serializer.hpp
index 67f45d8..4ed929a 100644
--- a/toml/serializer.hpp
+++ b/toml/serializer.hpp
@@ -2,11 +2,13 @@
 // Distributed under the MIT License.
 #ifndef TOML11_SERIALIZER_HPP
 #define TOML11_SERIALIZER_HPP
-#include "value.hpp"
-#include "lexer.hpp"
-#include <limits>
 #include <cstdio>
 
+#include <limits>
+
+#include "lexer.hpp"
+#include "value.hpp"
+
 namespace toml
 {
 
diff --git a/toml/source_location.hpp b/toml/source_location.hpp
index f85c51e..8c14b96 100644
--- a/toml/source_location.hpp
+++ b/toml/source_location.hpp
@@ -2,9 +2,10 @@
 // Distributed under the MIT License.
 #ifndef TOML11_SOURCE_LOCATION_HPP
 #define TOML11_SOURCE_LOCATION_HPP
-#include "region.hpp"
 #include <cstdint>
 
+#include "region.hpp"
+
 namespace toml
 {
 
diff --git a/toml/string.hpp b/toml/string.hpp
index 0551ccd..a6ed080 100644
--- a/toml/string.hpp
+++ b/toml/string.hpp
@@ -2,9 +2,11 @@
 // Distributed under the MIT License.
 #ifndef TOML11_STRING_HPP
 #define TOML11_STRING_HPP
+#include <cstdint>
+
 #include <algorithm>
 #include <string>
-#include <cstdint>
+
 #if __cplusplus >= 201703L
 #if __has_include(<string_view>)
 #include <string_view>
diff --git a/toml/traits.hpp b/toml/traits.hpp
index 31037f4..eafa6af 100644
--- a/toml/traits.hpp
+++ b/toml/traits.hpp
@@ -2,12 +2,13 @@
 // Distributed under the MIT License.
 #ifndef TOML11_TRAITS_HPP
 #define TOML11_TRAITS_HPP
+#include <chrono>
+#include <forward_list>
+#include <string>
+#include <tuple>
 #include <type_traits>
 #include <utility>
-#include <chrono>
-#include <tuple>
-#include <string>
-#include <forward_list>
+
 #if __cplusplus >= 201703L
 #if __has_include(<string_view>)
 #include <string_view>
diff --git a/toml/types.hpp b/toml/types.hpp
index b289d2d..0818ebd 100644
--- a/toml/types.hpp
+++ b/toml/types.hpp
@@ -2,12 +2,13 @@
 // Distributed under the MIT License.
 #ifndef TOML11_TYPES_HPP
 #define TOML11_TYPES_HPP
+#include <unordered_map>
+#include <vector>
+
+#include "comments.hpp"
 #include "datetime.hpp"
 #include "string.hpp"
 #include "traits.hpp"
-#include "comments.hpp"
-#include <vector>
-#include <unordered_map>
 
 namespace toml
 {
diff --git a/toml/utility.hpp b/toml/utility.hpp
index c287b8e..113bec6 100644
--- a/toml/utility.hpp
+++ b/toml/utility.hpp
@@ -2,10 +2,11 @@
 // Distributed under the MIT License.
 #ifndef TOML11_UTILITY_HPP
 #define TOML11_UTILITY_HPP
-#include "traits.hpp"
-#include <utility>
 #include <memory>
 #include <sstream>
+#include <utility>
+
+#include "traits.hpp"
 
 #if __cplusplus >= 201402L
 #  define TOML11_MARK_AS_DEPRECATED(msg) [[deprecated(msg)]]
diff --git a/toml/value.hpp b/toml/value.hpp
index db48265..d2f8cb9 100644
--- a/toml/value.hpp
+++ b/toml/value.hpp
@@ -2,17 +2,18 @@
 // Distributed under the MIT License.
 #ifndef TOML11_VALUE_HPP
 #define TOML11_VALUE_HPP
-#include "traits.hpp"
-#include "into.hpp"
-#include "utility.hpp"
-#include "exception.hpp"
-#include "storage.hpp"
-#include "region.hpp"
-#include "types.hpp"
-#include "source_location.hpp"
-#include "comments.hpp"
 #include <cassert>
 
+#include "comments.hpp"
+#include "exception.hpp"
+#include "into.hpp"
+#include "region.hpp"
+#include "source_location.hpp"
+#include "storage.hpp"
+#include "traits.hpp"
+#include "types.hpp"
+#include "utility.hpp"
+
 namespace toml
 {