diff --git a/openpgp.d.ts b/openpgp.d.ts
index 795f3869..405a99b3 100644
--- a/openpgp.d.ts
+++ b/openpgp.d.ts
@@ -497,7 +497,8 @@ export class SignaturePacket extends BasePacket {
   public hashAlgorithm: enums.hash | null;
   public publicKeyAlgorithm: enums.publicKey | null;
   public signatureData: null | Uint8Array;
-  public unhashedSubpackets: null | Uint8Array;
+  public unhashedSubpackets: RawSubpacket[];
+  public unknownSubpackets: RawSubpacket[];
   public signedHashValue: null | Uint8Array;
   public created: Date | null;
   public signatureExpirationTime: null | number;
@@ -541,6 +542,12 @@ export class SignaturePacket extends BasePacket {
   public getExpirationTime(): Date | typeof Infinity;
 }
 
+export interface RawSubpacket {
+  type: number;
+  critical: boolean;
+  body: Uint8Array;
+}
+
 export interface RawNotation {
   name: string;
   value: Uint8Array;
diff --git a/src/packet/signature.js b/src/packet/signature.js
index 78a7963b..a6bbc8d5 100644
--- a/src/packet/signature.js
+++ b/src/packet/signature.js
@@ -396,10 +396,8 @@ class SignaturePacket {
    * @returns {Uint8Array} Subpacket data.
    */
   writeUnhashedSubPackets() {
-    const arr = [];
-    this.unhashedSubpackets.forEach(data => {
-      arr.push(writeSimpleLength(data.length));
-      arr.push(data);
+    const arr = this.unhashedSubpackets.map(({ type, critical, body }) => {
+      return writeSubPacket(type, critical, body);
     });
 
     const result = util.concat(arr);
@@ -408,7 +406,7 @@ class SignaturePacket {
     return util.concat([length, result]);
   }
 
-  // V4 signature sub packets
+  // Signature subpackets
   readSubPacket(bytes, hashed = true) {
     let mypos = 0;
 
@@ -416,15 +414,19 @@ class SignaturePacket {
     const critical = !!(bytes[mypos] & 0x80);
     const type = bytes[mypos] & 0x7F;
 
+    mypos++;
+
     if (!hashed) {
-      this.unhashedSubpackets.push(bytes.subarray(mypos, bytes.length));
+      this.unhashedSubpackets.push({
+        type,
+        critical,
+        body: bytes.subarray(mypos, bytes.length)
+      });
       if (!allowedUnhashedSubpackets.has(type)) {
         return;
       }
     }
 
-    mypos++;
-
     // subpacket type
     switch (type) {
       case enums.signatureSubpacket.signatureCreationTime: