diff --git a/src/main/java/com/gdschongik/gdsc/domain/study/application/StudentStudyHistoryService.java b/src/main/java/com/gdschongik/gdsc/domain/study/application/StudentStudyHistoryService.java
index 1cfa3bca9..327e9e291 100644
--- a/src/main/java/com/gdschongik/gdsc/domain/study/application/StudentStudyHistoryService.java
+++ b/src/main/java/com/gdschongik/gdsc/domain/study/application/StudentStudyHistoryService.java
@@ -26,7 +26,6 @@
 import com.gdschongik.gdsc.infra.github.client.GithubClient;
 import java.io.IOException;
 import java.time.LocalDateTime;
-import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -129,9 +128,6 @@ public List<StudentMyCompleteStudyResponse> getMyCompletedStudies() {
         return studyHistories.stream()
                 .map(history -> {
                     List<AchievementType> achievementTypes = achievementsByStudy.get(history.getStudy());
-                    if (achievementTypes == null) {
-                        achievementTypes = new ArrayList<>();
-                    }
                     return StudentMyCompleteStudyResponse.of(history, achievementTypes);
                 })
                 .toList();
diff --git a/src/main/java/com/gdschongik/gdsc/domain/study/dto/response/StudentMyCompleteStudyResponse.java b/src/main/java/com/gdschongik/gdsc/domain/study/dto/response/StudentMyCompleteStudyResponse.java
index a77dbdab5..6362a91f4 100644
--- a/src/main/java/com/gdschongik/gdsc/domain/study/dto/response/StudentMyCompleteStudyResponse.java
+++ b/src/main/java/com/gdschongik/gdsc/domain/study/dto/response/StudentMyCompleteStudyResponse.java
@@ -5,6 +5,7 @@
 import com.gdschongik.gdsc.domain.study.domain.StudyHistory;
 import com.gdschongik.gdsc.domain.study.domain.StudyHistoryStatus;
 import io.swagger.v3.oas.annotations.media.Schema;
+import java.util.ArrayList;
 import java.util.List;
 
 public record StudentMyCompleteStudyResponse(
@@ -32,6 +33,6 @@ public static StudentMyCompleteStudyResponse of(StudyHistory studyHistory, List<
                 studyHistory.getStudy().getMentor().getName(),
                 studyHistory.getStudy().getTotalWeek(),
                 studyHistory.getStudyHistoryStatus(),
-                achievements);
+                (achievements == null) ? new ArrayList<>() : achievements);
     }
 }