diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java
index e05e8458a..4c14aa2b1 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java
@@ -323,6 +323,7 @@ public abstract class AbstractTracingSpan implements AbstractSpan {
 
     @Override public AbstractSpan prepareForAsync() {
         context = ContextManager.awaitFinishAsync(this);
+        isInAsyncMode = true;
         return this;
     }