diff --git a/src/test/java/com/github/nkzawa/engineio/client/Connection.java b/src/test/java/com/github/nkzawa/engineio/client/Connection.java
index df961ce..48693ca 100644
--- a/src/test/java/com/github/nkzawa/engineio/client/Connection.java
+++ b/src/test/java/com/github/nkzawa/engineio/client/Connection.java
@@ -6,6 +6,8 @@ import org.junit.Before;
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.concurrent.*;
 
 public abstract class Connection {
@@ -78,6 +80,15 @@ public abstract class Connection {
     }
 
     String[] createEnv() {
-        return new String[] {"DEBUG=engine*", "PORT=" + PORT};
+        Map<String, String> env = new HashMap<String, String>(System.getenv());
+        env.put("DEBUG", "engine*");
+        env.put("PORT", String.valueOf(PORT));
+        String[] _env = new String[env.size()];
+        int i = 0;
+        for (String key : env.keySet()) {
+            _env[i] = key + "=" + env.get(key);
+            i++;
+        }
+        return _env;
     }
 }
diff --git a/src/test/java/com/github/nkzawa/engineio/client/executions/Connection.java b/src/test/java/com/github/nkzawa/engineio/client/executions/Connection.java
index 371ff1c..4e48f98 100644
--- a/src/test/java/com/github/nkzawa/engineio/client/executions/Connection.java
+++ b/src/test/java/com/github/nkzawa/engineio/client/executions/Connection.java
@@ -4,13 +4,11 @@ import com.github.nkzawa.emitter.Emitter;
 import com.github.nkzawa.engineio.client.Socket;
 
 import java.net.URISyntaxException;
-import java.util.Map;
 
 public class Connection {
 
     public static void main(String[] args) throws URISyntaxException {
-        Map<String, String> env = System.getenv();
-        final Socket socket = new Socket("http://localhost:" + env.get("PORT"));
+        final Socket socket = new Socket("http://localhost:" + System.getenv("PORT"));
         socket.on(Socket.EVENT_OPEN, new Emitter.Listener() {
             @Override
             public void call(Object... args) {
diff --git a/src/test/java/com/github/nkzawa/engineio/client/executions/ConnectionFailure.java b/src/test/java/com/github/nkzawa/engineio/client/executions/ConnectionFailure.java
index 371564c..f95b0ac 100644
--- a/src/test/java/com/github/nkzawa/engineio/client/executions/ConnectionFailure.java
+++ b/src/test/java/com/github/nkzawa/engineio/client/executions/ConnectionFailure.java
@@ -4,13 +4,11 @@ import com.github.nkzawa.emitter.Emitter;
 import com.github.nkzawa.engineio.client.Socket;
 
 import java.net.URISyntaxException;
-import java.util.Map;
 
 public class ConnectionFailure {
 
     public static void main(String[] args) throws URISyntaxException {
-        Map<String, String> env = System.getenv();
-        int port = Integer.parseInt(env.get("PORT"));
+        int port = Integer.parseInt(System.getenv("PORT"));
         port++;
         final Socket socket = new Socket("http://localhost:" + port);
         socket.on(Socket.EVENT_CLOSE, new Emitter.Listener() {
diff --git a/src/test/java/com/github/nkzawa/engineio/client/executions/ImmediateClose.java b/src/test/java/com/github/nkzawa/engineio/client/executions/ImmediateClose.java
index b5983ec..e89365f 100644
--- a/src/test/java/com/github/nkzawa/engineio/client/executions/ImmediateClose.java
+++ b/src/test/java/com/github/nkzawa/engineio/client/executions/ImmediateClose.java
@@ -4,13 +4,11 @@ import com.github.nkzawa.emitter.Emitter;
 import com.github.nkzawa.engineio.client.Socket;
 
 import java.net.URISyntaxException;
-import java.util.Map;
 
 public class ImmediateClose {
 
     public static void main(String[] args) throws URISyntaxException {
-        Map<String, String> env = System.getenv();
-        final Socket socket = new Socket("http://localhost:" + env.get("PORT"));
+        final Socket socket = new Socket("http://localhost:" + System.getenv("PORT"));
         socket.on(Socket.EVENT_OPEN, new Emitter.Listener() {
             @Override
             public void call(Object... args) {