diff --git a/src/main/java/com/souzip/domain/recommend/ai/service/AiRecommendationService.java b/src/main/java/com/souzip/domain/recommend/ai/service/AiRecommendationService.java
index c933ae64..dc5f131d 100644
--- a/src/main/java/com/souzip/domain/recommend/ai/service/AiRecommendationService.java
+++ b/src/main/java/com/souzip/domain/recommend/ai/service/AiRecommendationService.java
@@ -72,7 +72,6 @@ public AiRecommendationResponse getCategoryRecommendationsForUser(Long userId) {
         log.info("추천 이름 파싱: {}", recommendedNamesByCategory);
 
         String userUuid = findUserUuid(userId);
-
         return new AiRecommendationResponse(
                 mapToRecommendedSouvenirs(recommendedNamesByCategory, userUuid)
         );
@@ -125,7 +124,7 @@ public AiRecommendationResponse getRecentSouvenirRecommendations(Long userId) {
 
         String userUuid = findUserUuid(userId);
         List<Long> souvenirIds = souvenirs.stream().map(Souvenir::getId).toList();
-        Set<Long> wishlistedIds = wishlistRepository.findSouvenirIdsByUserId(userUuid);
+        Set<Long> wishlistedIds = wishlistRepository.findSouvenirIdsByUserUserId(userUuid);
         Map<Long, Long> wishlistCountMap = wishlistRepository.countBySouvenirIds(souvenirIds);
 
         List<AiRecommendationResponse.RecommendedSouvenir> finalSouvenirs = souvenirs.stream()
@@ -217,7 +216,7 @@ private List<AiRecommendationResponse.RecommendedSouvenir> mapToRecommendedSouve
                 .toList();
 
         Map<Long, FileResponse> thumbnailMap = getThumbnails(souvenirIds);
-        Set<Long> wishlistedIds = wishlistRepository.findSouvenirIdsByUserId(userUuid);
+        Set<Long> wishlistedIds = wishlistRepository.findSouvenirIdsByUserUserId(userUuid);
         Map<Long, Long> wishlistCountMap = wishlistRepository.countBySouvenirIds(souvenirIds);
 
         return souvenirs.stream()
diff --git a/src/main/java/com/souzip/domain/recommend/general/service/GeneralRecommendationService.java b/src/main/java/com/souzip/domain/recommend/general/service/GeneralRecommendationService.java
index 4267815e..b33f5f49 100644
--- a/src/main/java/com/souzip/domain/recommend/general/service/GeneralRecommendationService.java
+++ b/src/main/java/com/souzip/domain/recommend/general/service/GeneralRecommendationService.java
@@ -70,7 +70,7 @@ public List<CountryRecommendationDto> getTopCountriesWithTop10Souvenirs(@Nullabl
 
         String userId = extractUserId(authorizationHeader);
         Set<Long> wishlistedIds = userId != null
-                ? wishlistRepository.findSouvenirIdsByUserId(userId)
+                ? wishlistRepository.findSouvenirIdsByUserUserId(userId)
                 : Collections.emptySet();
         Map<Long, Long> wishlistCountMap = wishlistRepository.countBySouvenirIds(allSouvenirIds);
 
@@ -116,7 +116,7 @@ private List<GeneralRecommendationDto> toDto(List<Souvenir> souvenirs, @Nullable
 
         String userId = extractUserId(authorizationHeader);
         Set<Long> wishlistedIds = userId != null
-                ? wishlistRepository.findSouvenirIdsByUserId(userId)
+                ? wishlistRepository.findSouvenirIdsByUserUserId(userId)
                 : Collections.emptySet();
         Map<Long, Long> wishlistCountMap = wishlistRepository.countBySouvenirIds(souvenirIds);
 
diff --git a/src/main/java/com/souzip/domain/souvenir/service/SouvenirService.java b/src/main/java/com/souzip/domain/souvenir/service/SouvenirService.java
index 111a11a8..7437554b 100644
--- a/src/main/java/com/souzip/domain/souvenir/service/SouvenirService.java
+++ b/src/main/java/com/souzip/domain/souvenir/service/SouvenirService.java
@@ -56,12 +56,13 @@ public SouvenirNearbyListResponse getNearbySouvenirs(
             double radiusMeter,
             @Nullable String authorizationHeader
     ) {
-        String userId = extractUserId(authorizationHeader);
+        Long userId = extractUserIdAsLong(authorizationHeader);
 
         List<Object[]> results = souvenirRepository.findNearbySouvenirs(latitude, longitude, radiusMeter);
 
-        Set<Long> wishlistedIds = userId != null
-                ? wishlistRepository.findSouvenirIdsByUserId(userId)
+        String userUuid = userId != null ? findUserUuid(userId) : null;
+        Set<Long> wishlistedIds = userUuid != null
+                ? wishlistRepository.findSouvenirIdsByUserUserId(userUuid)
                 : Collections.emptySet();
 
         List<SouvenirNearbyResponse> list = results.stream()
@@ -79,11 +80,12 @@ public SouvenirDetailResponse getSouvenir(
             Long souvenirId,
             @Nullable String authorizationHeader
     ) {
-        String userId = extractUserId(authorizationHeader);
+        Long userId = extractUserIdAsLong(authorizationHeader);
         Souvenir souvenir = findSouvenirById(souvenirId);
         List<FileResponse> files = getFiles(souvenirId);
-        boolean isOwned = souvenir.isOwnedBy(userId);
-        boolean isWishlisted = userId != null && wishlistRepository.existsByUserUserIdAndSouvenirId(userId, souvenirId);
+        String userUuid = userId != null ? findUserUuid(userId) : null;
+        boolean isOwned = userId != null && souvenir.isOwnedBy(userUuid);
+        boolean isWishlisted = userUuid != null && wishlistRepository.existsByUserUserIdAndSouvenirId(userUuid, souvenirId);
         long wishlistCount = wishlistRepository.countBySouvenirId(souvenirId);
         PriceResponse priceResponse = createPriceResponse(souvenir);
         return SouvenirDetailResponse.of(souvenir, files, isOwned, isWishlisted, wishlistCount, priceResponse);
@@ -220,7 +222,7 @@ private PriceResponse createPriceResponse(Souvenir souvenir) {
     }
 
     @Nullable
-    private String extractUserId(@Nullable String authorizationHeader) {
+    private Long extractUserIdAsLong(@Nullable String authorizationHeader) {
         if (hasNoAuthorizationHeader(authorizationHeader)) {
             return null;
         }
@@ -235,7 +237,13 @@ private String extractUserId(@Nullable String authorizationHeader) {
             return null;
         }
 
-        return parseUserIdFromToken(token);
+        return parseUserIdFromTokenAsLong(token);
+    }
+
+    @Nullable
+    private String extractUserId(@Nullable String authorizationHeader) {
+        Long userId = extractUserIdAsLong(authorizationHeader);
+        return userId != null ? String.valueOf(userId) : null;
     }
 
     private boolean hasNoAuthorizationHeader(String authorizationHeader) {
@@ -255,16 +263,21 @@ private boolean isEmptyToken(String token) {
     }
 
     @Nullable
-    private String parseUserIdFromToken(String token) {
+    private Long parseUserIdFromTokenAsLong(String token) {
         try {
-            Long userId = jwtTokenProvider.getUserIdFromToken(token);
-            return userId != null ? String.valueOf(userId) : null;
+            return jwtTokenProvider.getUserIdFromToken(token);
         } catch (Exception e) {
             log.debug("Failed to parse token", e);
             return null;
         }
     }
 
+    private String findUserUuid(Long userId) {
+        return userRepository.findById(userId)
+                .map(User::getUserId)
+                .orElseThrow(() -> new BusinessException(ErrorCode.USER_NOT_FOUND));
+    }
+
     private void requireUserId(Long userId) {
         if (isNullUserId(userId)) {
             throw new BusinessException(ErrorCode.UNAUTHORIZED);
diff --git a/src/main/java/com/souzip/domain/user/service/UserService.java b/src/main/java/com/souzip/domain/user/service/UserService.java
index 92cb7665..d0fd2a22 100644
--- a/src/main/java/com/souzip/domain/user/service/UserService.java
+++ b/src/main/java/com/souzip/domain/user/service/UserService.java
@@ -119,7 +119,7 @@ public MySouvenirListResponse getMySouvenirs(Long userId, int page, int size) {
                 .toList();
 
         Map<Long, FileResponse> thumbnailMap = getThumbnails(souvenirIds);
-        Set<Long> wishlistedIds = wishlistRepository.findSouvenirIdsByUserId(user.getUserId());
+        Set<Long> wishlistedIds = wishlistRepository.findSouvenirIdsByUserUserId(user.getUserId());
         Map<Long, Long> wishlistCountMap = wishlistRepository.countBySouvenirIds(souvenirIds);
 
         Page<MySouvenirResponse> responsePage = souvenirPage.map(souvenir -> {
diff --git a/src/main/java/com/souzip/domain/wishlist/repository/WishlistRepository.java b/src/main/java/com/souzip/domain/wishlist/repository/WishlistRepository.java
index c4de3895..99e7ec60 100644
--- a/src/main/java/com/souzip/domain/wishlist/repository/WishlistRepository.java
+++ b/src/main/java/com/souzip/domain/wishlist/repository/WishlistRepository.java
@@ -17,6 +17,8 @@
 @Repository
 public interface WishlistRepository extends JpaRepository<Wishlist, Long> {
 
+    boolean existsByUserIdAndSouvenirId(Long userId, Long souvenirId);
+
     boolean existsByUserUserIdAndSouvenirId(String userId, Long souvenirId);
 
     @Modifying
@@ -29,8 +31,11 @@ public interface WishlistRepository extends JpaRepository<Wishlist, Long> {
     )
     Page<Wishlist> findByUserIdOrderByCreatedAtDesc(@Param("userId") Long userId, Pageable pageable);
 
+    @Query("SELECT w.souvenir.id FROM Wishlist w WHERE w.user.id = :userId")
+    Set<Long> findSouvenirIdsByUserId(@Param("userId") Long userId);
+
     @Query("SELECT w.souvenir.id FROM Wishlist w WHERE w.user.userId = :userId")
-    Set<Long> findSouvenirIdsByUserId(@Param("userId") String userId);
+    Set<Long> findSouvenirIdsByUserUserId(@Param("userId") String userId);
 
     @Query("SELECT COUNT(w) FROM Wishlist w WHERE w.souvenir.id = :souvenirId")
     long countBySouvenirId(@Param("souvenirId") Long souvenirId);