diff --git a/ext/nio4r/org/nio4r/ByteBuffer.java b/ext/nio4r/org/nio4r/ByteBuffer.java
index 05480f7..8764b7c 100644
--- a/ext/nio4r/org/nio4r/ByteBuffer.java
+++ b/ext/nio4r/org/nio4r/ByteBuffer.java
@@ -27,7 +27,7 @@
  */
 public class ByteBuffer extends RubyObject {
     private static final long serialVersionUID = -6903439483039149324L;
-    private java.nio.ByteBuffer byteBuffer;
+    private transient java.nio.ByteBuffer byteBuffer;
 
     public static RaiseException newOverflowError(ThreadContext context, String message) {
         RubyClass klass = context.runtime.getModule("NIO").getClass("ByteBuffer").getClass("OverflowError");
diff --git a/ext/nio4r/org/nio4r/Monitor.java b/ext/nio4r/org/nio4r/Monitor.java
index c723073..bfe5d1c 100644
--- a/ext/nio4r/org/nio4r/Monitor.java
+++ b/ext/nio4r/org/nio4r/Monitor.java
@@ -14,9 +14,9 @@
 
 public class Monitor extends RubyObject {
     private static final long serialVersionUID = -3733782997115074794L;
-    private SelectionKey key;
+    private transient SelectionKey key;
     private RubyIO io;
-    private IRubyObject interests, selector, value, closed;
+    private transient IRubyObject interests, selector, value, closed;
 
     public Monitor(final Ruby ruby, RubyClass rubyClass) {
         super(ruby, rubyClass);
diff --git a/ext/nio4r/org/nio4r/Selector.java b/ext/nio4r/org/nio4r/Selector.java
index 016ec35..99c0f28 100644
--- a/ext/nio4r/org/nio4r/Selector.java
+++ b/ext/nio4r/org/nio4r/Selector.java
@@ -22,7 +22,7 @@
 
 public class Selector extends RubyObject {
     private static final long serialVersionUID = -14562818539414873L;
-    private java.nio.channels.Selector selector;
+    private transient java.nio.channels.Selector selector;
     private HashMap<SelectableChannel,SelectionKey> cancelledKeys;
     private volatile boolean wakeupFired;
 
@@ -234,7 +234,7 @@ private int doSelect(Ruby runtime, ThreadContext context, IRubyObject timeout) {
 
         cancelKeys();
         try {
-            context.getThread().beforeBlockingCall();
+            context.getThread().beforeBlockingCall(context);
             if(timeout.isNil()) {
                 result = this.selector.select();
             } else {