diff --git a/src/main/java/cholog/discord/message/GithubPullRequestMergeSubscription.java b/src/main/java/cholog/discord/message/GithubPullRequestMergeSubscription.java
index 3a6fe98..b1064f4 100644
--- a/src/main/java/cholog/discord/message/GithubPullRequestMergeSubscription.java
+++ b/src/main/java/cholog/discord/message/GithubPullRequestMergeSubscription.java
@@ -4,6 +4,7 @@
 import cholog.github.PullRequest;
 import cholog.github.PullRequestMergeRequest;
 import cholog.github.PullRequestUrl;
+import feign.FeignException;
 import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -12,12 +13,15 @@
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Objects;
+import java.util.stream.Collectors;
 
 @Component
 public final class GithubPullRequestMergeSubscription implements MessageSubscription {
 
     private static final Logger log = LoggerFactory.getLogger(GithubPullRequestMergeSubscription.class);
 
+    public static final String DONE_EMOJI_ID = "1189497983142727770";
+
     private final MessagesProperties properties;
 
     private final GithubApi githubApi;
@@ -83,23 +87,33 @@ public void onEvent(final MessageReceivedEvent event) {
                     pullRequest.head().sha(),
                     PullRequestMergeRequest.MergeMethod.SQUASH
             );
-            final var mergeResult = githubApi.mergePullRequest(
-                    pullRequestUrl.owner(),
-                    pullRequestUrl.repository(),
-                    pullRequestUrl.pullNumber(),
-                    mergeRequest
-            );
-            if (!mergeResult.merged()) {
-                fails.put(url, mergeResult.message());
+            try {
+                final var mergeResult = githubApi.mergePullRequest(
+                        pullRequestUrl.owner(),
+                        pullRequestUrl.repository(),
+                        pullRequestUrl.pullNumber(),
+                        mergeRequest
+                );
+                if (!mergeResult.merged()) {
+                    fails.put(url, mergeResult.message());
+                }
+            } catch (final FeignException e) {
+                switch (e.status()) {
+                    case 403, 404, 409, 422 -> {
+                        log.error("Failed to merge PR [url={}]", url, e);
+                        fails.put(url, "PR 머지에 실패했습니다. 관리자에게 문의해주세요.");
+                    }
+                    case 405 -> fails.put(url, "이 PR은 머지할 수 없습니다. 머지가 가능한 상태인지 확인해주세요.");
+                }
             }
         }
 
-        final var doneEmoji = Objects.requireNonNull(message.getJDA().getEmojiById("1189497983142727770"));
+        final var doneEmoji = Objects.requireNonNull(message.getJDA().getEmojiById(DONE_EMOJI_ID));
         message.addReaction(doneEmoji).queue();
         if (!fails.isEmpty()) {
             final var failMessages = fails.entrySet().stream()
                     .map(entry -> entry.getKey() + ": " + entry.getValue())
-                    .collect(StringBuilder::new, StringBuilder::append, StringBuilder::append);
+                    .collect(Collectors.joining());
             message.reply(failMessages).queue();
         }
     }