diff --git a/src/lib/utils/contest.ts b/src/lib/utils/contest.ts
index e01c34a21..8413e69bb 100644
--- a/src/lib/utils/contest.ts
+++ b/src/lib/utils/contest.ts
@@ -95,6 +95,7 @@ export const classifyContest = (contest_id: string) => {
 // HACK: As of December 2024, the following contests are applicable.
 // Note: The classification logic may need to be revised when new contests are added.
 const ABC_LIKE: ContestPrefix = {
+  aising2020: 'エイシング プログラミング コンテスト 2020',
   panasonic2020: 'パナソニックプログラミングコンテスト 2020',
 } as const;
 const abcLikePrefixes = new Set(getContestPrefixes(ABC_LIKE));
@@ -162,7 +163,10 @@ const atCoderUniversityPrefixes = getContestPrefixes(ATCODER_UNIVERSITIES);
 const ATCODER_OTHERS: ContestPrefix = {
   chokudai_S: 'Chokudai SpeedRun',
   'code-festival-2014-final': 'Code Festival 2014 決勝',
+  'code-thanks-festival': 'CODE THANKS FESTIVAL',
   donuts: 'Donutsプロコンチャレンジ',
+  indeednow: 'Indeedなう',
+  'dwacon2017-prelims': '第3回 ドワンゴからの挑戦状 予選',
   'mujin-pc-2016': 'Mujin Programming Challenge 2016',
   'mujin-pc-2018': 'Mujin Programming Challenge 2018',
   'tenka1-2016-final': '天下一プログラマーコンテスト2016本戦',
diff --git a/src/test/lib/utils/test_cases/contest_type.ts b/src/test/lib/utils/test_cases/contest_type.ts
index f40989825..fe4704095 100644
--- a/src/test/lib/utils/test_cases/contest_type.ts
+++ b/src/test/lib/utils/test_cases/contest_type.ts
@@ -187,6 +187,10 @@ export const agc = agcContestIds.map((contestId) =>
 );
 
 export const abcLike = [
+  createTestCaseForContestType('AISing 2020')({
+    contestId: 'aising2020',
+    expected: ContestType.ABC_LIKE,
+  }),
   createTestCaseForContestType('Panasonic 2020')({
     contestId: 'panasonic2020',
     expected: ContestType.ABC_LIKE,
@@ -295,6 +299,14 @@ export const atCoderOthers = [
     contestId: 'code-festival-2014-final',
     expected: ContestType.OTHERS,
   }),
+  createTestCaseForContestType('CODE THANKS FESTIVAL 2017')({
+    contestId: 'code-thanks-festival-2017',
+    expected: ContestType.OTHERS,
+  }),
+  createTestCaseForContestType('CODE THANKS FESTIVAL 2018')({
+    contestId: 'code-thanks-festival-2018',
+    expected: ContestType.OTHERS,
+  }),
   createTestCaseForContestType('Donuts Procon Challenge 2014')({
     contestId: 'donuts-live2014',
     expected: ContestType.OTHERS,
@@ -303,6 +315,14 @@ export const atCoderOthers = [
     contestId: 'donuts-2015',
     expected: ContestType.OTHERS,
   }),
+  createTestCaseForContestType('IndeedNow Qual B')({
+    contestId: 'indeednow-qualb',
+    expected: ContestType.OTHERS,
+  }),
+  createTestCaseForContestType('第3回 ドワンゴからの挑戦状 予選')({
+    contestId: 'dwacon2017-prelims',
+    expected: ContestType.OTHERS,
+  }),
   createTestCaseForContestType('MUJIN Programming Challenge 2016')({
     contestId: 'mujin-pc-2016',
     expected: ContestType.OTHERS,