diff --git a/library/src/main/java/com/rafakob/nsdhelper/NsdHelper.java b/library/src/main/java/com/rafakob/nsdhelper/NsdHelper.java
index db6399d..e12df79 100644
--- a/library/src/main/java/com/rafakob/nsdhelper/NsdHelper.java
+++ b/library/src/main/java/com/rafakob/nsdhelper/NsdHelper.java
@@ -269,7 +269,9 @@ int findAvaiablePort() {
         ServerSocket socket;
         try {
             socket = new ServerSocket(0);
-            return socket.getLocalPort();
+            int socketNumber = socket.getLocalPort();
+            socket.close();
+            return socketNumber;
         } catch (IOException e) {
             logError("Couldn't assign port to your service.", 0, "java.net.ServerSocket");
             e.printStackTrace();