diff --git a/handler/src/main/java/io/netty/handler/timeout/IdleStateEvent.java b/handler/src/main/java/io/netty/handler/timeout/IdleStateEvent.java
index bb476e7a9a..6617daa834 100644
--- a/handler/src/main/java/io/netty/handler/timeout/IdleStateEvent.java
+++ b/handler/src/main/java/io/netty/handler/timeout/IdleStateEvent.java
@@ -19,6 +19,8 @@ import static java.util.Objects.requireNonNull;
 
 import io.netty.channel.Channel;
 
+import io.netty.util.internal.StringUtil;
+
 /**
  * A user event triggered by {@link IdleStateHandler} when a {@link Channel} is idle.
  */
@@ -32,6 +34,7 @@ public class IdleStateEvent {
 
     private final IdleState state;
     private final boolean first;
+    private String strVal;
 
     /**
      * Constructor for sub-classes.
@@ -57,4 +60,12 @@ public class IdleStateEvent {
     public boolean isFirst() {
         return first;
     }
+
+    @Override
+    public String toString() {
+        if (strVal == null) {
+            strVal = StringUtil.simpleClassName(this) + "(" + state + (first ? ", first" : "") + ')';
+        }
+        return strVal;
+    }
 }
diff --git a/handler/src/test/java/io/netty/handler/timeout/IdleStateEventTest.java b/handler/src/test/java/io/netty/handler/timeout/IdleStateEventTest.java
new file mode 100644
index 0000000000..5e2d25e0ed
--- /dev/null
+++ b/handler/src/test/java/io/netty/handler/timeout/IdleStateEventTest.java
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2019 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.handler.timeout;
+
+import org.junit.Test;
+
+import static io.netty.handler.timeout.IdleStateEvent.*;
+import static org.hamcrest.Matchers.hasToString;
+import static org.junit.Assert.*;
+
+public class IdleStateEventTest {
+    @Test
+    public void testHumanReadableToString() {
+        assertThat(FIRST_READER_IDLE_STATE_EVENT, hasToString("IdleStateEvent(READER_IDLE, first)"));
+        assertThat(READER_IDLE_STATE_EVENT, hasToString("IdleStateEvent(READER_IDLE)"));
+        assertThat(FIRST_WRITER_IDLE_STATE_EVENT, hasToString("IdleStateEvent(WRITER_IDLE, first)"));
+        assertThat(WRITER_IDLE_STATE_EVENT, hasToString("IdleStateEvent(WRITER_IDLE)"));
+        assertThat(FIRST_ALL_IDLE_STATE_EVENT, hasToString("IdleStateEvent(ALL_IDLE, first)"));
+        assertThat(ALL_IDLE_STATE_EVENT, hasToString("IdleStateEvent(ALL_IDLE)"));
+    }
+}