diff --git a/src/main/java/com/renzzle/backend/domain/puzzle/training/service/TrainingService.java b/src/main/java/com/renzzle/backend/domain/puzzle/training/service/TrainingService.java
index 9f0e1a8e..a6030094 100644
--- a/src/main/java/com/renzzle/backend/domain/puzzle/training/service/TrainingService.java
+++ b/src/main/java/com/renzzle/backend/domain/puzzle/training/service/TrainingService.java
@@ -167,7 +167,11 @@ public SolveTrainingPuzzleResponse solveTrainingPuzzle(UserEntity user, Long puz
             case "HIGH" -> TRAINING_HIGH_REWARD.getPrice();
             default -> 0;
         };
-        if(getReward) user.getReward(reward);
+        if(getReward){
+            UserEntity persistentUser = userRepository.findById(user.getId())
+                    .orElseThrow(() -> new CustomException(ErrorCode.CANNOT_FIND_USER));
+            persistentUser.getReward(reward);
+        }
 
         return SolveTrainingPuzzleResponse.builder()
                 .reward(reward)
diff --git a/src/test/java/com/renzzle/backend/domain/puzzle/training/service/TrainingServiceTest.java b/src/test/java/com/renzzle/backend/domain/puzzle/training/service/TrainingServiceTest.java
index 9c8dba2f..94972284 100644
--- a/src/test/java/com/renzzle/backend/domain/puzzle/training/service/TrainingServiceTest.java
+++ b/src/test/java/com/renzzle/backend/domain/puzzle/training/service/TrainingServiceTest.java
@@ -306,6 +306,10 @@ public void testSolveLessonPuzzle() {
             when(trainingPuzzleRepository.findById(puzzleId))
                     .thenReturn(Optional.of(trainingPuzzle));
 
+            // 사용자 조회 성공 (영속 상태의 엔티티 반환)
+            when(userRepository.findById(userId))
+                    .thenReturn(Optional.of(user));
+
             // 저장 결과 더미 설정
             when(solvedTrainingPuzzleRepository.save(any(SolvedTrainingPuzzle.class)))
                     .thenAnswer(invocation -> invocation.getArgument(0));