diff --git a/onlinejudge/service/atcoder.py b/onlinejudge/service/atcoder.py
index e558f24..48903f1 100644
--- a/onlinejudge/service/atcoder.py
+++ b/onlinejudge/service/atcoder.py
@@ -542,10 +542,10 @@ def _from_table_row(cls, tr: bs4.Tag, *, session: requests.Session, response: re
             time_limit_msec = int(float(utils.remove_suffix(tds[2].text, ' sec')) * 1000)
         else:
             assert False
-        if tds[3].text.endswith(' KB'):
-            memory_limit_byte = int(float(utils.remove_suffix(tds[3].text, ' KB')) * 1000)
-        elif tds[3].text.endswith(' MB'):
-            memory_limit_byte = int(float(utils.remove_suffix(tds[3].text, ' MB')) * 1000 * 1000)  # TODO: confirm this is MB truly, not MiB
+        if tds[3].text.endswith(' KiB'):
+            memory_limit_byte = int(float(utils.remove_suffix(tds[3].text, ' KiB')) * 1024)
+        elif tds[3].text.endswith(' MiB'):
+            memory_limit_byte = int(float(utils.remove_suffix(tds[3].text, ' MiB')) * 1024 * 1024)  # TODO: confirm this is MB truly, not MiB
         else:
             assert False
         if len(tds) == 5:
@@ -583,15 +583,15 @@ def _from_html(cls, html: bytes, *, problem: 'AtCoderProblem', session: Optional
             assert False
 
         # When login as the admin, a link is added after memory limit. See https://github.com/online-judge-tools/api-client/issues/90
-        parsed_memory_limit = re.search(r'^(メモリ制限|Memory Limit): ([0-9.]+) (KB|MB)', memory_limit)
+        parsed_memory_limit = re.search(r'^(メモリ制限|Memory Limit): ([0-9.]+) (KiB|MiB)', memory_limit)
         assert parsed_memory_limit
 
         memory_limit_value = parsed_memory_limit.group(2)
         memory_limit_unit = parsed_memory_limit.group(3)
-        if memory_limit_unit == 'KB':
-            memory_limit_byte = int(float(memory_limit_value) * 1000)
-        elif memory_limit_unit == 'MB':
-            memory_limit_byte = int(float(memory_limit_value) * 1000 * 1000)
+        if memory_limit_unit == 'KiB':
+            memory_limit_byte = int(float(memory_limit_value) * 1024)
+        elif memory_limit_unit == 'MiB':
+            memory_limit_byte = int(float(memory_limit_value) * 1024 * 1024)
         else:
             assert False
 
@@ -1160,7 +1160,7 @@ def _from_table_row(cls, tr: bs4.Tag, *, session: requests.Session, response: re
         status = tds[6].text
         if len(tds) == 10:
             exec_time_msec = int(utils.remove_suffix(tds[7].text, ' ms'))  # type: Optional[int]
-            memory_byte = int(utils.remove_suffix(tds[8].text, ' KB')) * 1000  # type: Optional[int]
+            memory_byte = int(utils.remove_suffix(tds[8].text, ' KiB')) * 1024  # type: Optional[int]
         else:
             exec_time_msec = None
             memory_byte = None
diff --git a/onlinejudge_api/get_problem.py b/onlinejudge_api/get_problem.py
index f357ff8..9d7fdec 100644
--- a/onlinejudge_api/get_problem.py
+++ b/onlinejudge_api/get_problem.py
@@ -67,7 +67,7 @@
         },
         "memoryLimit": {
             "type": "integer",
-            "description": "in megabytes (MB), not in mebibytes (MiB); Decimals are truncated for compatibility to competitive-companion",
+            "description": "in mebibytes (MiB), not in megabytes (MB); Decimals are truncated for compatibility to competitive-companion",
         },
         "timeLimit": {
             "type": "integer",
@@ -316,7 +316,7 @@ def main(problem: Problem, *, is_system: bool, is_compatibility: bool, is_full:
             },
             "alphabet": data.alphabet,
         }
-        result["memoryLimit"] = data.memory_limit_byte // 1000 // 1000
+        result["memoryLimit"] = data.memory_limit_byte // 1024 // 1024
         result["timeLimit"] = data.time_limit_msec
         if is_full:
             result["raw"] = {
diff --git a/tests/service_atcoder.py b/tests/service_atcoder.py
index e7a1b1d..924c2fc 100644
--- a/tests/service_atcoder.py
+++ b/tests/service_atcoder.py
@@ -84,7 +84,7 @@ def test_list_problems(self):
         time.sleep(0.5)
         self.assertEqual(problems[0].download_data().time_limit_msec, 2000)
         time.sleep(0.5)
-        self.assertEqual(problems[0].download_data().memory_limit_byte, 1024 * 1000 * 1000)
+        self.assertEqual(problems[0].download_data().memory_limit_byte, 1024 * 1024 * 1024)
         time.sleep(0.5)
         self.assertEqual(problems[5].download_data().alphabet, 'F')
         time.sleep(0.5)
@@ -106,11 +106,11 @@ def test_list_problems_with_float_values(self):
         time.sleep(0.5)
         self.assertEqual(problems[0].download_data().time_limit_msec, 2525)
         time.sleep(0.5)
-        self.assertEqual(problems[0].download_data().memory_limit_byte, 246 * 1000 * 1000)
+        self.assertEqual(problems[0].download_data().memory_limit_byte, 246 * 1024 * 1024)
         time.sleep(0.5)
         self.assertEqual(problems[1].download_data().time_limit_msec, 5252)
         time.sleep(0.5)
-        self.assertEqual(problems[1].download_data().memory_limit_byte, 512 * 1000 * 1000)
+        self.assertEqual(problems[1].download_data().memory_limit_byte, 512 * 1024 * 1024)
 
     def test_list_problems_time_limit_is_less_than_msec(self):
         contest = AtCoderContest.from_url('https://atcoder.jp/contests/joi2019ho')
@@ -132,9 +132,9 @@ def test_list_problems_memory_limit_is_zero(self):
         time.sleep(0.5)
         problems = contest.list_problems()
         time.sleep(0.5)
-        self.assertEqual(problems[0].download_data().memory_limit_byte, 1024 * 1000 * 1000)  # 1024 MB
+        self.assertEqual(problems[0].download_data().memory_limit_byte, 1024 * 1024 * 1024)  # 1024 MiB
         time.sleep(0.5)
-        self.assertEqual(problems[1].download_data().memory_limit_byte, 0)  # 0 KB
+        self.assertEqual(problems[1].download_data().memory_limit_byte, 0)  # 0 KiB
 
     @unittest.skip('Breaking change in AtCoder')
     def test_iterate_submissions(self):
@@ -195,7 +195,7 @@ def test_load_details(self):
         self.assertEqual(data.alphabet, 'A')
         self.assertEqual(data.name, 'B +/- A')
         self.assertEqual(data.time_limit_msec, 2000)
-        self.assertEqual(data.memory_limit_byte, 1024 * 1000 * 1000)
+        self.assertEqual(data.memory_limit_byte, 1024 * 1024 * 1024)
         self.assertEqual(data.score, 100)
 
     def test_get_alphabet(self):
@@ -259,7 +259,7 @@ def test_from_html_very_old(self):
         self.assertEqual(data.available_languages, None)
         self.assertEqual(data.html, html)
         self.assertEqual(data.input_format, None)
-        self.assertEqual(data.memory_limit_byte, 292 * 1000 * 1000)
+        self.assertEqual(data.memory_limit_byte, 292 * 1024 * 1024)
         self.assertEqual(data.name, 'プログラミングコンテスト')
         self.assertEqual(data.problem, AtCoderProblem.from_url(url))
         self.assertEqual(data.sample_cases, [
@@ -281,7 +281,7 @@ def test_from_html_old(self):
         self.assertEqual(data.available_languages, None)
         self.assertEqual(data.html, html)
         self.assertEqual(data.input_format, '\r\n<var>R</var> <var>C</var>\r\n<var>X</var> <var>Y</var>\r\n<var>D</var> <var>L</var>\r\n')
-        self.assertEqual(data.memory_limit_byte, 64 * 1000 * 1000)
+        self.assertEqual(data.memory_limit_byte, 64 * 1024 * 1024)
         self.assertEqual(data.name, 'AtCoder社の冬')
         self.assertEqual(data.problem, AtCoderProblem.from_url(url))
         self.assertEqual(data.sample_cases, [
@@ -304,7 +304,7 @@ def test_from_html_standard(self):
         self.assertEqual(data.available_languages, None)
         self.assertEqual(data.html, html)
         self.assertEqual(data.input_format, '<var>N</var>\r\n')
-        self.assertEqual(data.memory_limit_byte, 1024 * 1000 * 1000)
+        self.assertEqual(data.memory_limit_byte, 1024 * 1024 * 1024)
         self.assertEqual(data.name, '756')
         self.assertEqual(data.problem, AtCoderProblem.from_url(url))
         self.assertEqual(data.sample_cases, [
@@ -326,7 +326,7 @@ def test_from_html_with_empty_output(self):
         self.assertEqual(data.available_languages, None)
         self.assertEqual(data.html, html)
         self.assertEqual(data.input_format, '<var>N</var> <var>K</var>\r\n<var>A_0</var> <var>A_1</var> <var>\\cdots</var> <var>A_{N-1}</var>\r\n')
-        self.assertEqual(data.memory_limit_byte, 1024 * 1000 * 1000)
+        self.assertEqual(data.memory_limit_byte, 1024 * 1024 * 1024)
         self.assertEqual(data.name, 'Do Not Duplicate')
         self.assertEqual(data.problem, AtCoderProblem.from_url(url))
         self.assertEqual(data.sample_cases, [
@@ -349,7 +349,7 @@ def test_from_html_without_sample_cases(self):
         self.assertEqual(data.available_languages, None)
         self.assertEqual(data.html, html)
         self.assertEqual(data.input_format, None)
-        self.assertEqual(data.memory_limit_byte, 64 * 1000 * 1000)
+        self.assertEqual(data.memory_limit_byte, 64 * 1024 * 1024)
         self.assertEqual(data.name, '天下一株式会社採用情報')
         self.assertEqual(data.problem, AtCoderProblem.from_url(url))
         self.assertEqual(data.sample_cases, [])
@@ -367,7 +367,7 @@ def test_from_html_issue_414(self):
         self.assertEqual(data.available_languages, None)
         self.assertEqual(data.html, html)
         self.assertEqual(data.input_format, None)
-        self.assertEqual(data.memory_limit_byte, 256 * 1000 * 1000)
+        self.assertEqual(data.memory_limit_byte, 256 * 1024 * 1024)
         self.assertEqual(data.name, 'Graph Cut')
         self.assertEqual(data.problem, AtCoderProblem.from_url(url))
         self.assertEqual(data.sample_cases, [