diff --git a/atcoder/all b/atcoder/all
index 112458e..666568e 100644
--- a/atcoder/all
+++ b/atcoder/all
@@ -1,12 +1,12 @@
-#include <atcoder/convolution>
-#include <atcoder/dsu>
-#include <atcoder/fenwicktree>
-#include <atcoder/lazysegtree>
-#include <atcoder/math>
-#include <atcoder/maxflow>
-#include <atcoder/mincostflow>
-#include <atcoder/modint>
-#include <atcoder/scc>
-#include <atcoder/segtree>
-#include <atcoder/string>
-#include <atcoder/twosat>
+#include "atcoder/convolution"
+#include "atcoder/dsu"
+#include "atcoder/fenwicktree"
+#include "atcoder/lazysegtree"
+#include "atcoder/math"
+#include "atcoder/maxflow"
+#include "atcoder/mincostflow"
+#include "atcoder/modint"
+#include "atcoder/scc"
+#include "atcoder/segtree"
+#include "atcoder/string"
+#include "atcoder/twosat"
diff --git a/atcoder/convolution b/atcoder/convolution
index 4668477..a768486 100644
--- a/atcoder/convolution
+++ b/atcoder/convolution
@@ -1 +1 @@
-#include <atcoder/convolution.hpp>
+#include "atcoder/convolution.hpp"
diff --git a/atcoder/convolution.hpp b/atcoder/convolution.hpp
index 04cc20f..166e356 100644
--- a/atcoder/convolution.hpp
+++ b/atcoder/convolution.hpp
@@ -3,12 +3,13 @@
 
 #include <algorithm>
 #include <array>
-#include <atcoder/internal_bit>
-#include <atcoder/modint>
 #include <cassert>
 #include <type_traits>
 #include <vector>
 
+#include "atcoder/internal_bit"
+#include "atcoder/modint"
+
 namespace atcoder {
 
 namespace internal {
diff --git a/atcoder/dsu b/atcoder/dsu
index 846e8cb..8052180 100644
--- a/atcoder/dsu
+++ b/atcoder/dsu
@@ -1 +1 @@
-#include <atcoder/dsu.hpp>
+#include "atcoder/dsu.hpp"
diff --git a/atcoder/fenwicktree b/atcoder/fenwicktree
index f2febd1..c7371dc 100644
--- a/atcoder/fenwicktree
+++ b/atcoder/fenwicktree
@@ -1 +1 @@
-#include <atcoder/fenwicktree.hpp>
+#include "atcoder/fenwicktree.hpp"
diff --git a/atcoder/fenwicktree.hpp b/atcoder/fenwicktree.hpp
index 3e49e90..ab7c63b 100644
--- a/atcoder/fenwicktree.hpp
+++ b/atcoder/fenwicktree.hpp
@@ -1,10 +1,11 @@
 #ifndef ATCODER_FENWICKTREE_HPP
 #define ATCODER_FENWICKTREE_HPP 1
 
-#include <atcoder/internal_type_traits>
 #include <cassert>
 #include <vector>
 
+#include "atcoder/internal_type_traits"
+
 namespace atcoder {
 
 // Reference: https://en.wikipedia.org/wiki/Fenwick_tree
diff --git a/atcoder/internal_bit b/atcoder/internal_bit
index c7443cc..a24ec48 100644
--- a/atcoder/internal_bit
+++ b/atcoder/internal_bit
@@ -1 +1 @@
-#include <atcoder/internal_bit.hpp>
+#include "atcoder/internal_bit.hpp"
diff --git a/atcoder/internal_math b/atcoder/internal_math
index b228a70..84042f5 100644
--- a/atcoder/internal_math
+++ b/atcoder/internal_math
@@ -1 +1 @@
-#include <atcoder/internal_math.hpp>
+#include "atcoder/internal_math.hpp"
diff --git a/atcoder/internal_queue b/atcoder/internal_queue
index 9cb49b3..36cca9d 100644
--- a/atcoder/internal_queue
+++ b/atcoder/internal_queue
@@ -1 +1 @@
-#include <atcoder/internal_queue.hpp>
+#include "atcoder/internal_queue.hpp"
diff --git a/atcoder/internal_scc b/atcoder/internal_scc
index 21d8865..fd49944 100644
--- a/atcoder/internal_scc
+++ b/atcoder/internal_scc
@@ -1 +1 @@
-#include <atcoder/internal_scc.hpp>
+#include "atcoder/internal_scc.hpp"
diff --git a/atcoder/internal_type_traits b/atcoder/internal_type_traits
index 87fd106..31b2695 100644
--- a/atcoder/internal_type_traits
+++ b/atcoder/internal_type_traits
@@ -1 +1 @@
-#include <atcoder/internal_type_traits.hpp>
+#include "atcoder/internal_type_traits.hpp"
diff --git a/atcoder/lazysegtree b/atcoder/lazysegtree
index 7323e25..0f3875f 100644
--- a/atcoder/lazysegtree
+++ b/atcoder/lazysegtree
@@ -1 +1 @@
-#include <atcoder/lazysegtree.hpp>
+#include "atcoder/lazysegtree.hpp"
diff --git a/atcoder/lazysegtree.hpp b/atcoder/lazysegtree.hpp
index 8d23989..e9c0c63 100644
--- a/atcoder/lazysegtree.hpp
+++ b/atcoder/lazysegtree.hpp
@@ -2,10 +2,12 @@
 #define ATCODER_LAZYSEGTREE_HPP 1
 
 #include <algorithm>
-#include <atcoder/internal_bit>
 #include <cassert>
 #include <iostream>
 #include <vector>
+
+#include "atcoder/internal_bit"
+
 namespace atcoder {
 
 template <class S,
diff --git a/atcoder/math b/atcoder/math
index 52992a7..0636021 100644
--- a/atcoder/math
+++ b/atcoder/math
@@ -1 +1 @@
-#include <atcoder/math.hpp>
+#include "atcoder/math.hpp"
diff --git a/atcoder/math.hpp b/atcoder/math.hpp
index dd68ca9..ec5bca5 100644
--- a/atcoder/math.hpp
+++ b/atcoder/math.hpp
@@ -5,7 +5,8 @@
 #include <cassert>
 #include <tuple>
 #include <vector>
-#include <atcoder/internal_math>
+
+#include "atcoder/internal_math"
 
 namespace atcoder {
 
diff --git a/atcoder/maxflow b/atcoder/maxflow
index 64d215c..66df972 100644
--- a/atcoder/maxflow
+++ b/atcoder/maxflow
@@ -1 +1 @@
-#include <atcoder/maxflow.hpp>
+#include "atcoder/maxflow.hpp"
diff --git a/atcoder/maxflow.hpp b/atcoder/maxflow.hpp
index 6f535b9..d74cfad 100644
--- a/atcoder/maxflow.hpp
+++ b/atcoder/maxflow.hpp
@@ -2,12 +2,13 @@
 #define ATCODER_MAXFLOW_HPP 1
 
 #include <algorithm>
-#include <atcoder/internal_queue>
 #include <cassert>
 #include <limits>
 #include <queue>
 #include <vector>
 
+#include "atcoder/internal_queue"
+
 namespace atcoder {
 
 template <class Cap> struct mf_graph {
diff --git a/atcoder/mincostflow b/atcoder/mincostflow
index f6c451e..ed3ad2a 100644
--- a/atcoder/mincostflow
+++ b/atcoder/mincostflow
@@ -1 +1 @@
-#include <atcoder/mincostflow.hpp>
+#include "atcoder/mincostflow.hpp"
diff --git a/atcoder/modint b/atcoder/modint
index a0dfdc3..1aeaacb 100644
--- a/atcoder/modint
+++ b/atcoder/modint
@@ -1 +1 @@
-#include <atcoder/modint.hpp>
+#include "atcoder/modint.hpp"
diff --git a/atcoder/modint.hpp b/atcoder/modint.hpp
index 78df9ef..a00a650 100644
--- a/atcoder/modint.hpp
+++ b/atcoder/modint.hpp
@@ -1,8 +1,6 @@
 #ifndef ATCODER_MODINT_HPP
 #define ATCODER_MODINT_HPP 1
 
-#include <atcoder/internal_math>
-#include <atcoder/internal_type_traits>
 #include <cassert>
 #include <numeric>
 #include <type_traits>
@@ -11,6 +9,9 @@
 #include <intrin.h>
 #endif
 
+#include "atcoder/internal_math"
+#include "atcoder/internal_type_traits"
+
 namespace atcoder {
 
 namespace internal {
diff --git a/atcoder/scc b/atcoder/scc
index 6fda4bf..cdf451a 100644
--- a/atcoder/scc
+++ b/atcoder/scc
@@ -1 +1 @@
-#include <atcoder/scc.hpp>
+#include "atcoder/scc.hpp"
diff --git a/atcoder/scc.hpp b/atcoder/scc.hpp
index 6623b76..29e120f 100644
--- a/atcoder/scc.hpp
+++ b/atcoder/scc.hpp
@@ -2,10 +2,11 @@
 #define ATCODER_SCC_HPP 1
 
 #include <algorithm>
-#include <atcoder/internal_scc>
 #include <cassert>
 #include <vector>
 
+#include "atcoder/internal_scc"
+
 namespace atcoder {
 
 struct scc_graph {
diff --git a/atcoder/segtree b/atcoder/segtree
index 60a0d88..150f785 100644
--- a/atcoder/segtree
+++ b/atcoder/segtree
@@ -1 +1 @@
-#include <atcoder/segtree.hpp>
+#include "atcoder/segtree.hpp"
diff --git a/atcoder/segtree.hpp b/atcoder/segtree.hpp
index 31e1662..789fa33 100644
--- a/atcoder/segtree.hpp
+++ b/atcoder/segtree.hpp
@@ -2,10 +2,11 @@
 #define ATCODER_SEGTREE_HPP 1
 
 #include <algorithm>
-#include <atcoder/internal_bit>
 #include <cassert>
 #include <vector>
 
+#include "atcoder/internal_bit"
+
 namespace atcoder {
 
 template <class S, S (*op)(S, S), S (*e)()> struct segtree {
diff --git a/atcoder/string b/atcoder/string
index f4b40a1..7df6f26 100644
--- a/atcoder/string
+++ b/atcoder/string
@@ -1 +1 @@
-#include <atcoder/string.hpp>
+#include "atcoder/string.hpp"
diff --git a/atcoder/twosat b/atcoder/twosat
index 324a4c8..7e83c51 100644
--- a/atcoder/twosat
+++ b/atcoder/twosat
@@ -1 +1 @@
-#include <atcoder/twosat.hpp>
+#include "atcoder/twosat.hpp"
diff --git a/atcoder/twosat.hpp b/atcoder/twosat.hpp
index e16c443..25b9706 100644
--- a/atcoder/twosat.hpp
+++ b/atcoder/twosat.hpp
@@ -1,10 +1,11 @@
 #ifndef ATCODER_TWOSAT_HPP
 #define ATCODER_TWOSAT_HPP 1
 
-#include <atcoder/internal_scc>
 #include <cassert>
 #include <vector>
 
+#include "atcoder/internal_scc"
+
 namespace atcoder {
 
 // Reference:
diff --git a/expander.py b/expander.py
index ff41810..2f98f88 100755
--- a/expander.py
+++ b/expander.py
@@ -13,10 +13,12 @@
 
 
 class Expander:
+    local_include = re.compile(
+        r'#include\s*"([a-z_]*(|.hpp))"\s*')
     atcoder_include = re.compile(
-        '#include\s*["<](atcoder/[a-z_]*(|.hpp))[">]\s*')
+        r'#include\s*["<](atcoder/[a-z_]*(|.hpp))[">]\s*')
 
-    include_guard = re.compile('#.*ATCODER_[A-Z_]*_HPP')
+    include_guard = re.compile(r'#.*ATCODER_[A-Z_]*_HPP')
 
     def is_ignored_line(self, line) -> bool:
         if self.include_guard.match(line):
@@ -30,27 +32,24 @@ def is_ignored_line(self, line) -> bool:
     def __init__(self, lib_paths: List[Path]):
         self.lib_paths = lib_paths
 
-    included = set()  # type: Set[str]
+    included = set()  # type: Set[Path]
 
-    def find_acl(self, acl_name: str) -> Optional[Path]:
+    def find_acl(self, acl_name: str) -> Path:
         for lib_path in self.lib_paths:
             path = lib_path / acl_name
             if path.exists():
                 return path
-        return None
+        logger.error('cannot find: {}'.format(acl_name))
+        raise FileNotFoundError()
 
-    def expand_acl(self, acl_name: str) -> List[str]:
-        if acl_name in self.included:
-            logger.info('already included: {}'.format(acl_name))
+    def expand_acl(self, acl_file_path: Path) -> List[str]:
+        if acl_file_path in self.included:
+            logger.info('already included: {}'.format(acl_file_path.name))
             return []
-        self.included.add(acl_name)
-        logger.info('include: {}'.format(acl_name))
-        acl_path = self.find_acl(acl_name)
-        if not acl_path:
-            logger.warning('cannot find: {}'.format(acl_name))
-            raise FileNotFoundError()
+        self.included.add(acl_file_path)
+        logger.info('include: {}'.format(acl_file_path.name))
 
-        acl_source = open(str(acl_path)).read()
+        acl_source = open(str(acl_file_path)).read()
 
         result = []  # type: List[str]
         for line in acl_source.splitlines():
@@ -59,7 +58,14 @@ def expand_acl(self, acl_name: str) -> List[str]:
 
             m = self.atcoder_include.match(line)
             if m:
-                result.extend(self.expand_acl(m.group(1)))
+                name = m.group(1)
+                result.extend(self.expand_acl(self.find_acl(name)))
+                continue
+            
+            m = self.local_include.match(line)
+            if m:
+                name = m.group(1)
+                result.extend(self.expand_acl(acl_file_path.parent / name))
                 continue
 
             result.append(line)
@@ -71,10 +77,11 @@ def expand(self, source: str) -> str:
         result = []  # type: List[str]
         for line in source.splitlines():
             m = self.atcoder_include.match(line)
-
             if m:
-                result.extend(self.expand_acl(m.group(1)))
+                acl_path = self.find_acl(m.group(1))
+                result.extend(self.expand_acl(acl_path))
                 continue
+
             result.append(line)
         return '\n'.join(result)
 
diff --git a/test/unittest/basic_test.cpp b/test/unittest/basic_test.cpp
index 28a298b..777aacf 100644
--- a/test/unittest/basic_test.cpp
+++ b/test/unittest/basic_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/all>
+#include "atcoder/all"
+
 #include <type_traits>
 
 #include <gtest/gtest.h>
diff --git a/test/unittest/bit_test.cpp b/test/unittest/bit_test.cpp
index 802e013..18e38f4 100644
--- a/test/unittest/bit_test.cpp
+++ b/test/unittest/bit_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/internal_bit>
+#include "atcoder/internal_bit"
+
 #include <numeric>
 
 #include <gtest/gtest.h>
diff --git a/test/unittest/convolution_test.cpp b/test/unittest/convolution_test.cpp
index 90cc480..cf8f55a 100644
--- a/test/unittest/convolution_test.cpp
+++ b/test/unittest/convolution_test.cpp
@@ -1,5 +1,6 @@
-#include <atcoder/convolution>
-#include <atcoder/modint>
+#include "atcoder/convolution"
+#include "atcoder/modint"
+
 #include <random>
 #include "../utils/random.hpp"
 
diff --git a/test/unittest/dsu_test.cpp b/test/unittest/dsu_test.cpp
index 1797b2d..cca95e3 100644
--- a/test/unittest/dsu_test.cpp
+++ b/test/unittest/dsu_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/dsu>
+#include "atcoder/dsu"
+
 #include <numeric>
 
 #include <gtest/gtest.h>
diff --git a/test/unittest/fenwicktree_test.cpp b/test/unittest/fenwicktree_test.cpp
index e00a331..17ffc78 100644
--- a/test/unittest/fenwicktree_test.cpp
+++ b/test/unittest/fenwicktree_test.cpp
@@ -1,5 +1,6 @@
-#include <atcoder/fenwicktree>
-#include <atcoder/modint>
+#include "atcoder/fenwicktree"
+#include "atcoder/modint"
+
 #include <numeric>
 
 #include <gtest/gtest.h>
diff --git a/test/unittest/internal_math_test.cpp b/test/unittest/internal_math_test.cpp
index 014847b..7e26406 100644
--- a/test/unittest/internal_math_test.cpp
+++ b/test/unittest/internal_math_test.cpp
@@ -1,8 +1,9 @@
-#include <gtest/gtest.h>
-#include <numeric>
+#include "atcoder/internal_math"
+
 #include "../utils/math.hpp"
 
-#include <atcoder/internal_math>
+#include <gtest/gtest.h>
+#include <numeric>
 
 using namespace atcoder;
 using uint = unsigned int;
diff --git a/test/unittest/lazysegtree_stress_test.cpp b/test/unittest/lazysegtree_stress_test.cpp
index 8da3a52..f45ffec 100644
--- a/test/unittest/lazysegtree_stress_test.cpp
+++ b/test/unittest/lazysegtree_stress_test.cpp
@@ -1,6 +1,8 @@
-#include <algorithm>
-#include <atcoder/lazysegtree>
+#include "atcoder/lazysegtree"
+
 #include "../utils/random.hpp"
+
+#include <algorithm>
 #include <string>
 #include <vector>
 
diff --git a/test/unittest/lazysegtree_test.cpp b/test/unittest/lazysegtree_test.cpp
index ff2d7e0..d408a6b 100644
--- a/test/unittest/lazysegtree_test.cpp
+++ b/test/unittest/lazysegtree_test.cpp
@@ -1,5 +1,6 @@
+#include "atcoder/lazysegtree"
+
 #include <algorithm>
-#include <atcoder/lazysegtree>
 #include <string>
 #include <vector>
 
diff --git a/test/unittest/math_test.cpp b/test/unittest/math_test.cpp
index e211c79..c2d80a9 100644
--- a/test/unittest/math_test.cpp
+++ b/test/unittest/math_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/math>
+#include "atcoder/math"
+
 #include <numeric>
 
 #include <gtest/gtest.h>
diff --git a/test/unittest/maxflow_test.cpp b/test/unittest/maxflow_test.cpp
index 44c1574..dbdf5b6 100644
--- a/test/unittest/maxflow_test.cpp
+++ b/test/unittest/maxflow_test.cpp
@@ -1,8 +1,9 @@
-#include <atcoder/maxflow>
+#include "atcoder/maxflow"
+#include "../utils/random.hpp"
+
 #include <numeric>
 #include <tuple>
 #include <vector>
-#include "../utils/random.hpp"
 
 #include <gtest/gtest.h>
 
diff --git a/test/unittest/mincostflow_test.cpp b/test/unittest/mincostflow_test.cpp
index 293b4ec..6db41cb 100644
--- a/test/unittest/mincostflow_test.cpp
+++ b/test/unittest/mincostflow_test.cpp
@@ -1,10 +1,11 @@
-#include <atcoder/maxflow>
-#include <atcoder/mincostflow>
+#include "atcoder/maxflow"
+#include "atcoder/mincostflow"
+
+#include "../utils/random.hpp"
 
 #include <numeric>
 #include <tuple>
 #include <vector>
-#include "../utils/random.hpp"
 
 #include <gtest/gtest.h>
 
diff --git a/test/unittest/modint_test.cpp b/test/unittest/modint_test.cpp
index 9229eeb..81f33cc 100644
--- a/test/unittest/modint_test.cpp
+++ b/test/unittest/modint_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/modint>
+#include "atcoder/modint"
+
 #include <type_traits>
 
 #include <gtest/gtest.h>
diff --git a/test/unittest/scc_test.cpp b/test/unittest/scc_test.cpp
index 4124a73..50b7cc8 100644
--- a/test/unittest/scc_test.cpp
+++ b/test/unittest/scc_test.cpp
@@ -1,5 +1,5 @@
-#include <atcoder/scc>
-#include <atcoder/modint>
+#include "atcoder/scc"
+#include "atcoder/modint"
 #include <numeric>
 
 #include <gtest/gtest.h>
diff --git a/test/unittest/segtree_test.cpp b/test/unittest/segtree_test.cpp
index e95ae6a..0f49e1c 100644
--- a/test/unittest/segtree_test.cpp
+++ b/test/unittest/segtree_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/segtree>
+#include "atcoder/segtree"
+
 #include <string>
 #include <vector>
 
diff --git a/test/unittest/string_test.cpp b/test/unittest/string_test.cpp
index c7ead7c..037f817 100644
--- a/test/unittest/string_test.cpp
+++ b/test/unittest/string_test.cpp
@@ -1,5 +1,6 @@
+#include "atcoder/string"
+
 #include <algorithm>
-#include <atcoder/string>
 #include <numeric>
 #include <vector>
 
diff --git a/test/unittest/twosat_test.cpp b/test/unittest/twosat_test.cpp
index cbf5b68..0122554 100644
--- a/test/unittest/twosat_test.cpp
+++ b/test/unittest/twosat_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/twosat>
+#include "atcoder/twosat"
+
 #include <numeric>
 #include "../utils/random.hpp"
 
diff --git a/test/unittest/type_traits_test.cpp b/test/unittest/type_traits_test.cpp
index 15ce726..aa4ca67 100644
--- a/test/unittest/type_traits_test.cpp
+++ b/test/unittest/type_traits_test.cpp
@@ -1,4 +1,5 @@
-#include <atcoder/internal_type_traits>
+#include "atcoder/internal_type_traits"
+
 #include <type_traits>
 
 #include <gtest/gtest.h>