diff --git a/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/callback/DeferredResultHolder.java b/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/callback/DeferredResultHolder.java
index ac77f7b9..dbedcb65 100644
--- a/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/callback/DeferredResultHolder.java
+++ b/src/main/java/com/genersoft/iot/vmp/gb28181/transmit/callback/DeferredResultHolder.java
@@ -35,7 +35,7 @@ public class DeferredResultHolder {
 
 	public static final String CALLBACK_CMD_PLAY = "CALLBACK_PLAY";
 
-	public static final String CALLBACK_CMD_PLAYBACK = "CALLBACK_PLAY";
+	public static final String CALLBACK_CMD_PLAYBACK = "CALLBACK_PLAYBACK";
 
 	public static final String CALLBACK_CMD_DOWNLOAD = "CALLBACK_DOWNLOAD";