diff --git a/openpgp.d.ts b/openpgp.d.ts
index b4d54b5b..d5bd60ae 100644
--- a/openpgp.d.ts
+++ b/openpgp.d.ts
@@ -383,7 +383,7 @@ declare abstract class BasePublicKeyPacket extends BasePacket {
   public hasSameFingerprintAs(other: BasePublicKeyPacket): boolean;
   public getCreationTime(): Date;
   public getKeyID(): KeyID;
-  public isDecrypted(): boolean;
+  public isDecrypted(): boolean | null;
   public publicParams: object;
   // `isSubkey` is a dummy method to ensure that Subkey packets are not accepted as Key one, and vice versa.
   // The key class hierarchy is already modelled to cover this, but the concrete key packet classes
@@ -394,11 +394,13 @@ declare abstract class BasePublicKeyPacket extends BasePacket {
 export class PublicKeyPacket extends BasePublicKeyPacket {
   static readonly tag: enums.packet.publicKey;
   protected isSubkey(): false;
+  public isDecrypted(): null;
 }
 
 export class PublicSubkeyPacket extends BasePublicKeyPacket {
   static readonly tag: enums.packet.publicSubkey;
   protected isSubkey(): true;
+  public isDecrypted(): null;
 }
 
 declare abstract class BaseSecretKeyPacket extends BasePublicKeyPacket {
@@ -406,6 +408,7 @@ declare abstract class BaseSecretKeyPacket extends BasePublicKeyPacket {
   public encrypt(passphrase: string, config?: Config): Promise<void>; // throws on error
   public decrypt(passphrase: string): Promise<void>; // throws on error
   public validate(): Promise<void>; // throws on error
+  public isDecrypted(): boolean;
   public isDummy(): boolean;
   public isMissingSecretKeyMaterial(): boolean;
   public makeDummy(config?: Config): void;
diff --git a/src/key/helper.js b/src/key/helper.js
index e803acab..fbc219b4 100644
--- a/src/key/helper.js
+++ b/src/key/helper.js
@@ -469,3 +469,5 @@ export function checkKeyRequirements(keyPacket, config) {
       break;
   }
 }
+
+export const isPublicOrDummyKeyPacket = keyPacket => keyPacket.isDecrypted() === null || keyPacket.isDummy();
diff --git a/src/key/key.js b/src/key/key.js
index 0fd87662..318e4dfa 100644
--- a/src/key/key.js
+++ b/src/key/key.js
@@ -274,8 +274,8 @@ class Key {
       throw util.wrapError('Could not verify primary key', err);
     }
     const subkeys = this.subkeys.slice().sort((a, b) => {
-      const aIsPrivate = a.isDecrypted() !== null && !a.isDummy();
-      const bIsPrivate = b.isDecrypted() !== null && !b.isDummy();
+      const aIsPrivate = !helper.isPublicOrDummyKeyPacket(a.keyPacket);
+      const bIsPrivate = !helper.isPublicOrDummyKeyPacket(b.keyPacket);
       const diffIsPrivate = bIsPrivate - aIsPrivate;
       // return non-dummy private (sub)keys first
       return diffIsPrivate !== 0 ? diffIsPrivate : b.keyPacket.created - a.keyPacket.created;
diff --git a/src/key/private_key.js b/src/key/private_key.js
index a90f02b7..b255eb34 100644
--- a/src/key/private_key.js
+++ b/src/key/private_key.js
@@ -83,8 +83,8 @@ class PrivateKey extends PublicKey {
     let exception = null;
     for (let i = 0; i < this.subkeys.length; i++) {
       if (!keyID || this.subkeys[i].getKeyID().equals(keyID, true)) {
-        if (this.subkeys[i].keyPacket.isDummy()) {
-          exception = exception || new Error('Gnu-dummy key packets cannot be used for decryption');
+        if (helper.isPublicOrDummyKeyPacket(this.subkeys[i].keyPacket)) {
+          exception = exception || new Error('Public or gnu-dummy key packets cannot be used for decryption');
           continue;
         }
 
@@ -103,8 +103,8 @@ class PrivateKey extends PublicKey {
     // evaluate primary key
     const selfCertification = await this.getPrimarySelfSignature(date, userID, config);
     if ((!keyID || primaryKey.getKeyID().equals(keyID, true)) && helper.validateDecryptionKeyPacket(primaryKey, selfCertification, config)) {
-      if (primaryKey.isDummy()) {
-        exception = exception || new Error('Gnu-dummy key packets cannot be used for decryption');
+      if (helper.isPublicOrDummyKeyPacket(primaryKey)) {
+        exception = exception || new Error('Public or gnu-dummy key packets cannot be used for decryption');
       } else {
         keys.push(this);
       }
diff --git a/test/general/key.js b/test/general/key.js
index 995c32b5..57b40d84 100644
--- a/test/general/key.js
+++ b/test/general/key.js
@@ -3019,6 +3019,64 @@ export default () => describe('Key', function() {
     expect(key.write()).to.deep.equal(expectedSerializedKey.data);
   });
 
+  it('Parsing armored key with public primary key and private subkeys', async function() {
+    // public primary key with:
+    // - one signing private subkey
+    // - one signing public subkey
+    // - one encryption private subkey
+    // - one encryption public subkey
+    const privateKeyWithPublicKeyPackets = await openpgp.readKey({ armoredKey: `-----BEGIN PGP PRIVATE KEY BLOCK-----
+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+=OKHa
+-----END PGP PRIVATE KEY BLOCK-----` });
+
+    expect(privateKeyWithPublicKeyPackets.isDecrypted()).to.be.true;
+    expect(privateKeyWithPublicKeyPackets.isPrivate()).to.be.true;
+    const signingKey = await privateKeyWithPublicKeyPackets.getSigningKey();
+    expect(signingKey.getKeyID().equals(privateKeyWithPublicKeyPackets.subkeys[0].getKeyID())).to.be.true;
+    const decryptedKeys = await privateKeyWithPublicKeyPackets.getDecryptionKeys();
+    expect(decryptedKeys.length).to.equal(1);
+    expect(decryptedKeys[0].getKeyID().equals(privateKeyWithPublicKeyPackets.subkeys[2].getKeyID())).to.be.true;
+  });
+
   it('Parses V5 sample key', async function() {
     // sec   ed25519 2019-03-20 [SC]
     //       19347BC9872464025F99DF3EC2E0000ED9884892E1F7B3EA4C94009159569B54