diff --git a/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexClient.java b/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexClient.java
index 7cca53d..70a56ad 100644
--- a/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexClient.java
+++ b/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexClient.java
@@ -28,7 +28,7 @@ public void startAndAwait() {
       pool.execute(sender);
       pool.execute(receiver);
 
-      Thread.sleep(sendMessages * 1000);
+      Thread.sleep(30 * 1000);
       pool.shutdownNow();
     } catch (InterruptedException | IOException e) {
       e.printStackTrace();
diff --git a/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexServer.java b/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexServer.java
index 35fd678..172af2f 100644
--- a/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexServer.java
+++ b/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexServer.java
@@ -32,7 +32,7 @@ public void startAndAwait() {
       pool.execute(sender);
       pool.execute(receiver);
 
-      Thread.sleep((sendMessages + 2) * 1000);
+      Thread.sleep(30 * 1000);
       pool.shutdownNow();
     } catch (InterruptedException | IOException e) {
       e.printStackTrace();
diff --git a/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexTest.java b/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexTest.java
index 8a1a6db..86dcb75 100644
--- a/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexTest.java
+++ b/src/test/java/org/scalasbt/ipcsocket/duplex/DuplexTest.java
@@ -28,7 +28,7 @@ public void testDuplexCommunication() throws Exception {
           pool.execute(() -> client.startAndAwait());
 
           // wait client and server to terminate
-          Thread.sleep((Math.max(serverSendMessages, clientSendMessages) + 1) * 1000);
+          Thread.sleep((Math.max(serverSendMessages, clientSendMessages) + 3) * 1000);
           pool.shutdown();
 
           assertEquals(serverSendMessages, client.receiver.receivedMessages);