diff --git a/src/key.js b/src/key.js
index 66625a47..85cf5ea1 100644
--- a/src/key.js
+++ b/src/key.js
@@ -470,7 +470,7 @@ function getExpirationTime(keyPacket, selfCertificate) {
     return new Date(keyPacket.created.getTime() + keyPacket.expirationTimeV3*24*3600*1000);
   }
   // check V4 expiration time
-  if (this.primaryKey.version == 4 && selfCertificate.keyNeverExpires === false) {
+  if (keyPacket.version == 4 && selfCertificate.keyNeverExpires === false) {
     return new Date(keyPacket.created.getTime() + selfCertificate.keyExpirationTime*1000);
   }
   return null;
diff --git a/test/general/key.js b/test/general/key.js
index 75657025..16d9757c 100644
--- a/test/general/key.js
+++ b/test/general/key.js
@@ -293,5 +293,20 @@ describe('Key', function() {
     expect(status).to.equal(openpgp.enums.keyStatus.revoked);
     done();
   });
+
+  it('Method getExpirationTime V4 Key', function() {
+    var pubKey = openpgp.key.readArmored(twoKeys).keys[1];
+    expect(pubKey).to.exist;
+    expect(pubKey).to.be.an.instanceof(openpgp.key.Key);
+    expect(pubKey.getExpirationTime().toISOString()).to.be.equal('2018-11-26T10:58:29.000Z');
+  });
+
+  it('Method getExpirationTime V4 SubKey', function() {
+    var pubKey = openpgp.key.readArmored(twoKeys).keys[1];
+    expect(pubKey).to.exist;
+    expect(pubKey).to.be.an.instanceof(openpgp.key.Key);
+    expect(pubKey.subKeys[0].getExpirationTime().toISOString()).to.be.equal('2018-11-26T10:58:29.000Z');
+  });
+
 });