diff --git a/src/main/java/com/dowe/util/s3/S3PresignedUrlGenerator.java b/src/main/java/com/dowe/util/s3/S3PresignedUrlGenerator.java
index 74121b4..6027961 100644
--- a/src/main/java/com/dowe/util/s3/S3PresignedUrlGenerator.java
+++ b/src/main/java/com/dowe/util/s3/S3PresignedUrlGenerator.java
@@ -30,6 +30,7 @@ public String generatePresignedUrl(
         .bucket(bucketName)
         .key(key)
         .acl("public-read")
+        .contentType("image/png")
         .build();
 
     PutObjectPresignRequest presignRequest = PutObjectPresignRequest.builder()