1 files changed, 4 insertions, 2 deletions
diff --git a/src/org/traccar/BaseProtocolDecoder.java b/src/org/traccar/BaseProtocolDecoder.java
index 630fe9a69..657e56258 100644
--- a/src/org/traccar/BaseProtocolDecoder.java
+++ b/src/org/traccar/BaseProtocolDecoder.java
@@ -46,8 +46,10 @@ public abstract class BaseProtocolDecoder extends OneToOneDecoder {
     }
 
     public BaseProtocolDecoder(ServerManager serverManager) {
-        this.serverManager = serverManager;
-        dataManager = serverManager.getDataManager();
+        if (serverManager != null) {
+            this.serverManager = serverManager;
+            dataManager = serverManager.getDataManager();
+        }
     }
 
 }