diff --git a/core/src/main/java/com/linecorp/armeria/common/NonBlocking.java b/core/src/main/java/com/linecorp/armeria/common/NonBlocking.java
index dc33cd3a19c..cceeef41ff2 100644
--- a/core/src/main/java/com/linecorp/armeria/common/NonBlocking.java
+++ b/core/src/main/java/com/linecorp/armeria/common/NonBlocking.java
@@ -16,6 +16,15 @@
 package com.linecorp.armeria.common;
 
 /**
- * A dummy interface that indicates non-blocking thread.
+ * An interface that indicates a non-blocking thread. You can use this interface to check if the current
+ * thread is a non-blocking thread. For example:
+ * <pre>{@code
+ * if (Thread.currentThread() instanceof NonBlocking) {
+ *     // Avoid blocking operations.
+ *     closeable.closeAsync();
+ * } else {
+ *     closeable.close();
+ * }
+ * }</pre>
  */
 public interface NonBlocking {}
diff --git a/core/src/main/java/com/linecorp/armeria/internal/common/util/EventLoopThread.java b/core/src/main/java/com/linecorp/armeria/internal/common/util/EventLoopThread.java
index c8d36aa43f3..ac082c940e3 100644
--- a/core/src/main/java/com/linecorp/armeria/internal/common/util/EventLoopThread.java
+++ b/core/src/main/java/com/linecorp/armeria/internal/common/util/EventLoopThread.java
@@ -23,7 +23,7 @@
 
 /**
  * An event loop thread with support for {@link TemporaryThreadLocals}, Netty {@link FastThreadLocal} and
- * Project Reactor {@link NonBlocking}.
+ * {@link NonBlocking} interface.
  */
 public final class EventLoopThread extends FastThreadLocalThread implements NonBlocking {