diff --git a/core/src/main/java/hudson/util/UnbufferedBase64InputStream.java b/core/src/main/java/hudson/util/UnbufferedBase64InputStream.java
index 54de1b46db..c68ae7f65d 100644
--- a/core/src/main/java/hudson/util/UnbufferedBase64InputStream.java
+++ b/core/src/main/java/hudson/util/UnbufferedBase64InputStream.java
@@ -15,7 +15,9 @@ import java.util.Base64;
  *
  * @author Kohsuke Kawaguchi
  * @since 1.349
+ * @deprecated Use {@link java.util.Base64.Decoder#wrap}.
  */
+@Deprecated
 public class UnbufferedBase64InputStream extends FilterInputStream {
     private byte[] encoded = new byte[4];
     private byte[] decoded;