diff --git a/src/main/java/com/zaxxer/nuprocess/internal/LibC.java b/src/main/java/com/zaxxer/nuprocess/internal/LibC.java
index 5a0d24d..532bd9b 100644
--- a/src/main/java/com/zaxxer/nuprocess/internal/LibC.java
+++ b/src/main/java/com/zaxxer/nuprocess/internal/LibC.java
@@ -81,7 +81,7 @@ public static native int posix_spawnp(IntByReference restrict_pid, String restri
    // We can't use JNA direct mapping for syscall(), since it takes varargs.
    public interface SyscallLibrary extends Library
    {
-      public static final int SYS___pthread_chdir = 348;
+      public static final int SYS___pthread_chdir = System.getProperty("os.name").toLowerCase().contains("freebsd") ? 12 : 348;
 
       int syscall(int syscall_number, Object... args);
    }
diff --git a/src/main/java/com/zaxxer/nuprocess/osx/LibKevent.java b/src/main/java/com/zaxxer/nuprocess/osx/LibKevent.java
index da4990b..f2a6b1f 100644
--- a/src/main/java/com/zaxxer/nuprocess/osx/LibKevent.java
+++ b/src/main/java/com/zaxxer/nuprocess/osx/LibKevent.java
@@ -59,6 +59,7 @@ public static class Kevent extends Structure
       public int fflags;
       public NativeLong data;
       public Pointer udata;
+      public long[] ext = new long[4];
 
       public Kevent() {
           super();
@@ -72,7 +73,12 @@ public Kevent(Pointer p) {
       @Override
       protected List getFieldOrder()
       {
-         return Arrays.asList("ident", "filter", "flags", "fflags", "data", "udata");
+         String osname = System.getProperty("os.name").toLowerCase();
+         if(osname.contains("freebsd")){
+            return Arrays.asList("ident", "filter", "flags", "fflags", "data", "udata", "ext");
+         } else {
+            return Arrays.asList("ident", "filter", "flags", "fflags", "data", "udata");
+         }
       }
 
       Kevent EV_SET(long ident, int filter, int flags, int fflags, long data, Pointer udata)
diff --git a/src/main/java/com/zaxxer/nuprocess/osx/ProcessKqueue.java b/src/main/java/com/zaxxer/nuprocess/osx/ProcessKqueue.java
index 210bf23..4c1328e 100644
--- a/src/main/java/com/zaxxer/nuprocess/osx/ProcessKqueue.java
+++ b/src/main/java/com/zaxxer/nuprocess/osx/ProcessKqueue.java
@@ -16,10 +16,13 @@
 
 package com.zaxxer.nuprocess.osx;
 
-import static com.zaxxer.nuprocess.internal.LibC.WEXITSTATUS;
-import static com.zaxxer.nuprocess.internal.LibC.WIFEXITED;
-import static com.zaxxer.nuprocess.internal.LibC.WIFSIGNALED;
-import static com.zaxxer.nuprocess.internal.LibC.WTERMSIG;
+import com.sun.jna.Native;
+import com.sun.jna.Pointer;
+import com.sun.jna.ptr.IntByReference;
+import com.zaxxer.nuprocess.internal.BaseEventProcessor;
+import com.zaxxer.nuprocess.internal.LibC;
+import com.zaxxer.nuprocess.osx.LibKevent.Kevent;
+import com.zaxxer.nuprocess.osx.LibKevent.TimeSpec;
 
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -28,13 +31,7 @@
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.TimeUnit;
 
-import com.sun.jna.Native;
-import com.sun.jna.Pointer;
-import com.sun.jna.ptr.IntByReference;
-import com.zaxxer.nuprocess.internal.BaseEventProcessor;
-import com.zaxxer.nuprocess.internal.LibC;
-import com.zaxxer.nuprocess.osx.LibKevent.Kevent;
-import com.zaxxer.nuprocess.osx.LibKevent.TimeSpec;
+import static com.zaxxer.nuprocess.internal.LibC.*;
 
 /**
  * @author Brett Wooldridge
@@ -115,14 +112,14 @@ public void registerProcess(OsxProcess process)
          // We don't use the processEvents array here, since this method is not
          // called on the event processor thread.
          Kevent[] events = (Kevent[]) new Kevent().toArray(4);
-         // Listen for process exit (one-shot event)
-         events[0].EV_SET((long) pid, Kevent.EVFILT_PROC, Kevent.EV_ADD | Kevent.EV_RECEIPT | Kevent.EV_ONESHOT,
-                          Kevent.NOTE_EXIT | Kevent.NOTE_EXITSTATUS | Kevent.NOTE_REAP, 0L, pidPointer);
          // Listen for stdout and stderr data availability (events deleted automatically when file descriptors closed)
-         events[1].EV_SET(stdoutFd, Kevent.EVFILT_READ, Kevent.EV_ADD | Kevent.EV_RECEIPT, 0, 0L, pidPointer);
-         events[2].EV_SET(stderrFd, Kevent.EVFILT_READ, Kevent.EV_ADD | Kevent.EV_RECEIPT, 0, 0L, pidPointer);
+         events[0].EV_SET(stdoutFd, Kevent.EVFILT_READ, Kevent.EV_ADD | Kevent.EV_RECEIPT, 0, 0L, pidPointer);
+         events[1].EV_SET(stderrFd, Kevent.EVFILT_READ, Kevent.EV_ADD | Kevent.EV_RECEIPT, 0, 0L, pidPointer);
          // Listen for stdin data availability (initially disabled until user wants read, deleted automatically when file descriptor closed)
-         events[3].EV_SET(stdinFd, Kevent.EVFILT_WRITE, Kevent.EV_ADD | Kevent.EV_DISABLE | Kevent.EV_RECEIPT, 0, 0L, pidPointer);
+         events[2].EV_SET(stdinFd, Kevent.EVFILT_WRITE, Kevent.EV_ADD | Kevent.EV_DISABLE | Kevent.EV_RECEIPT, 0, 0L, pidPointer);
+         // Listen for process exit (one-shot event)
+         events[3].EV_SET((long) pid, Kevent.EVFILT_PROC, Kevent.EV_ADD | Kevent.EV_RECEIPT | Kevent.EV_ONESHOT,
+                          Kevent.NOTE_EXIT | Kevent.NOTE_EXITSTATUS | Kevent.NOTE_REAP, 0L, pidPointer);
 
          registerEvents(events, 4);
       } finally {