diff --git a/src/main/java/com/cloudbees/syslog/sender/TcpSyslogMessageSender.java b/src/main/java/com/cloudbees/syslog/sender/TcpSyslogMessageSender.java
index 249556f..620d0f6 100644
--- a/src/main/java/com/cloudbees/syslog/sender/TcpSyslogMessageSender.java
+++ b/src/main/java/com/cloudbees/syslog/sender/TcpSyslogMessageSender.java
@@ -288,6 +288,8 @@ public String toString() {
 
     @Override
     public void close() throws IOException {
-        this.socket.close();
+        if (socket != null) {
+            this.socket.close();
+        }
     }
 }