diff --git a/src/Packet/SecretKey.php b/src/Packet/SecretKey.php
index e5d59594..5464bc9e 100644
--- a/src/Packet/SecretKey.php
+++ b/src/Packet/SecretKey.php
@@ -22,12 +22,10 @@
     KeyAlgorithm,
     PacketTag,
     RSAKeySize,
-    S2kType,
     S2kUsage,
     SymmetricAlgorithm,
 };
 use OpenPGP\Type\{
-    KeyPacketInterface,
     KeyMaterialInterface,
     PublicKeyPacketInterface,
     SecretKeyPacketInterface,
diff --git a/src/Packet/SecretSubkey.php b/src/Packet/SecretSubkey.php
index 837c4293..9e29054b 100644
--- a/src/Packet/SecretSubkey.php
+++ b/src/Packet/SecretSubkey.php
@@ -13,11 +13,8 @@
 use OpenPGP\Enum\{
     CurveOid,
     DHKeySize,
-    HashAlgorithm,
     KeyAlgorithm,
-    PacketTag,
     RSAKeySize,
-    S2kType,
     S2kUsage,
     SymmetricAlgorithm,
 };
diff --git a/src/Packet/Signature.php b/src/Packet/Signature.php
index 065ff97a..7ab36d36 100644
--- a/src/Packet/Signature.php
+++ b/src/Packet/Signature.php
@@ -30,7 +30,6 @@
     KeyPacketInterface,
     LiteralDataInterface,
     NotationDataInterface,
-    PublicKeyPacketInterface,
     SignaturePacketInterface,
     SecretKeyMaterialInterface,
     SubkeyPacketInterface,