diff --git a/backend/src/main/java/com/bootme/post/service/PostService.java b/backend/src/main/java/com/bootme/post/service/PostService.java
index 3eaa15e9..b292fa4c 100644
--- a/backend/src/main/java/com/bootme/post/service/PostService.java
+++ b/backend/src/main/java/com/bootme/post/service/PostService.java
@@ -83,7 +83,7 @@ public CustomPageImpl<PostResponse> findAllPosts(Long memberId, int page, int si
         boolean isLogin = authService.validateLogin(memberId);
         Predicate combinedPredicate = getCombinedPredicate(params);
         Set<Long> viewedPosts = getViewedPosts();
-        String topic = params.get("topic").get(0);
+        String topic = params.getOrDefault("topic", Collections.singletonList("")).get(0);
         String search = params.getOrDefault("search", Collections.singletonList("")).get(0);
 
         Page<PostResponse> postResponses = postRepositoryProxy.getPostPage(page, size, sort, topic, search, combinedPredicate)