diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java
index 130ea554..e26fb804 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/OpenPgpMetadata.java
@@ -27,6 +27,12 @@ import org.pgpainless.key.OpenPgpFingerprint;
 import org.pgpainless.key.SubkeyIdentifier;
 import org.pgpainless.util.SessionKey;
 
+/**
+ * Legacy class containing metadata about an OpenPGP message.
+ * It is advised to use {@link MessageMetadata} instead.
+ *
+ * TODO: Remove in 1.5.X
+ */
 public class OpenPgpMetadata {
 
     private final Set<Long> recipientKeyIds;