diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java
index 10970fc2..893036b1 100644
--- a/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/generation/KeyRingBuilder.java
@@ -54,6 +54,8 @@ import org.pgpainless.util.Passphrase;
 
 public class KeyRingBuilder implements KeyRingBuilderInterface<KeyRingBuilder> {
 
+    private static final long YEAR_IN_SECONDS = 1000L * 60 * 60 * 24 * 365;
+
     @SuppressWarnings("CharsetObjectCanBeUsed")
     private final Charset UTF8 = Charset.forName("UTF-8");
 
@@ -61,7 +63,7 @@ public class KeyRingBuilder implements KeyRingBuilderInterface<KeyRingBuilder> {
     private final List<KeySpec> subkeySpecs = new ArrayList<>();
     private final Map<String, SelfSignatureSubpackets.Callback> userIds = new LinkedHashMap<>();
     private Passphrase passphrase = Passphrase.emptyPassphrase();
-    private Date expirationDate = null;
+    private Date expirationDate = new Date(new Date().getTime() + YEAR_IN_SECONDS * 5); // Expiration in 5 yeras
 
     @Override
     public KeyRingBuilder setPrimaryKey(@Nonnull KeySpec keySpec) {
@@ -97,7 +99,13 @@ public class KeyRingBuilder implements KeyRingBuilderInterface<KeyRingBuilder> {
     }
 
     @Override
-    public KeyRingBuilder setExpirationDate(@Nonnull Date expirationDate) {
+    public KeyRingBuilder setExpirationDate(@Nullable Date expirationDate) {
+        if (expirationDate == null) {
+            // No expiration
+            this.expirationDate = null;
+            return this;
+        }
+
         Date now = new Date();
         if (now.after(expirationDate)) {
             throw new IllegalArgumentException("Expiration date must be in the future.");
diff --git a/pgpainless-core/src/test/java/org/pgpainless/key/modification/OldSignatureSubpacketsArePreservedOnNewSigTest.java b/pgpainless-core/src/test/java/org/pgpainless/key/modification/OldSignatureSubpacketsArePreservedOnNewSigTest.java
index 54ed88d7..b8c3244e 100644
--- a/pgpainless-core/src/test/java/org/pgpainless/key/modification/OldSignatureSubpacketsArePreservedOnNewSigTest.java
+++ b/pgpainless-core/src/test/java/org/pgpainless/key/modification/OldSignatureSubpacketsArePreservedOnNewSigTest.java
@@ -5,7 +5,6 @@
 package org.pgpainless.key.modification;
 
 import static org.junit.jupiter.api.Assertions.assertArrayEquals;
-import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 
@@ -38,7 +37,7 @@ public class OldSignatureSubpacketsArePreservedOnNewSigTest {
         assertNotNull(oldSignature);
         PGPSignatureSubpacketVector oldPackets = oldSignature.getHashedSubPackets();
 
-        assertEquals(0, oldPackets.getKeyExpirationTime());
+        long oldExpiration = oldPackets.getKeyExpirationTime();
 
         Date now = new Date();
         Date t1 = new Date(now.getTime() + millisInHour);
@@ -51,7 +50,7 @@ public class OldSignatureSubpacketsArePreservedOnNewSigTest {
         assertNotNull(newSignature);
         PGPSignatureSubpacketVector newPackets = newSignature.getHashedSubPackets();
 
-        assertNotEquals(0, newPackets.getKeyExpirationTime());
+        assertNotEquals(oldExpiration, newPackets.getKeyExpirationTime());
 
         assertArrayEquals(oldPackets.getPreferredHashAlgorithms(), newPackets.getPreferredHashAlgorithms());
     }