diff --git a/jcpp-infrastructure-queue/src/main/java/sanbing/jcpp/infrastructure/queue/common/QueueConstants.java b/jcpp-infrastructure-queue/src/main/java/sanbing/jcpp/infrastructure/queue/common/QueueConstants.java
index c2ac400..509bc52 100644
--- a/jcpp-infrastructure-queue/src/main/java/sanbing/jcpp/infrastructure/queue/common/QueueConstants.java
+++ b/jcpp-infrastructure-queue/src/main/java/sanbing/jcpp/infrastructure/queue/common/QueueConstants.java
@@ -12,6 +12,4 @@ public final class QueueConstants {
     public static final String MSG_MD_PREFIX = "jcpp_";
 
     public static final String MSG_MD_TS = "ts";
-
-    public static final String MSG_MD_PROTOCOL_SESSION_ID = "protocol_session_id";
 }
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