diff --git a/src/main/java/net/logstash/logback/composite/FastISOTimestampFormatter.java b/src/main/java/net/logstash/logback/composite/FastISOTimestampFormatter.java
index bcf526bb..19dcbb2e 100644
--- a/src/main/java/net/logstash/logback/composite/FastISOTimestampFormatter.java
+++ b/src/main/java/net/logstash/logback/composite/FastISOTimestampFormatter.java
@@ -20,6 +20,8 @@
 import java.time.ZoneOffset;
 import java.time.format.DateTimeFormatter;
 import java.time.zone.ZoneOffsetTransition;
+import java.time.zone.ZoneRules;
+import java.util.List;
 
 /**
  * A fast alternative to DateTimeFormatter when formatting millis using an ISO format.
@@ -167,12 +169,13 @@ private class ZoneOffsetState {
             
             Instant now = Instant.ofEpochMilli(timestampInMillis);
             ZoneOffset zoneOffset;
-            
+
+            ZoneRules rules = zoneId.getRules();
             /*
              * The Zone has a fixed offset that will never change.
              */
-            if (zoneId.getRules().isFixedOffset()) {
-                zoneOffset = zoneId.getRules().getOffset(now);
+            if (rules.isFixedOffset()) {
+                zoneOffset = rules.getOffset(now);
                 this.zoneTransitionStart = 0;
                 this.zoneTransitionStop = Long.MAX_VALUE;
             }
@@ -181,7 +184,12 @@ private class ZoneOffsetState {
              * and how long it is valid.
              */
             else {
-                ZoneOffsetTransition zoneOffsetTransition = zoneId.getRules().nextTransition(now);
+                ZoneOffsetTransition zoneOffsetTransition = rules.nextTransition(now);
+                if (zoneOffsetTransition == null) {
+                    List<ZoneOffsetTransition> transitions = rules.getTransitions();
+                    zoneOffsetTransition = transitions.get(transitions.size() - 1);
+                }
+
                 this.zoneTransitionStart = timestampInMillis;
                 this.zoneTransitionStop = zoneOffsetTransition.toEpochSecond() * 1_000;
                 zoneOffset = zoneOffsetTransition.getOffsetBefore();
diff --git a/src/test/java/net/logstash/logback/composite/FastISOTimestampFormatterTest.java b/src/test/java/net/logstash/logback/composite/FastISOTimestampFormatterTest.java
index c65bc202..97fd2d8b 100644
--- a/src/test/java/net/logstash/logback/composite/FastISOTimestampFormatterTest.java
+++ b/src/test/java/net/logstash/logback/composite/FastISOTimestampFormatterTest.java
@@ -18,6 +18,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatCode;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.assertj.core.api.Assertions.assertThatNoException;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -267,8 +268,14 @@ protected ZoneRules provideRules(String zoneId, boolean forCaching) {
             assertThat(invokeTwice(fast, after.toInstant())).isEqualTo(formatter.format(after));
         });
     }
-    
-    
+
+    /*
+     * Assert after the last transitions are not exception
+     */
+    @Test
+    public void afterTheLastTransition() {
+        assertThatNoException().isThrownBy(() -> FastISOTimestampFormatter.isoOffsetDateTime(ZoneId.of("Asia/Bangkok")));
+    }
     
     /*
      * Invoke same formatter from concurrent threads. Force invalidation of the cache by making