diff --git a/src/libthread/FreeBSD.c b/src/libthread/FreeBSD.c
index 77c4869..0fdb54b 100644
--- a/src/libthread/FreeBSD.c
+++ b/src/libthread/FreeBSD.c
@@ -1,11 +1,3 @@
-#include "u.h"
-#include <errno.h>
-#include <sys/types.h>
-#include <sys/wait.h>
-#include <sched.h>
-#include <signal.h>
-#include "libc.h"
-#include "thread.h"
 #include "threadimpl.h"
 
 extern int __isthreaded;
@@ -70,7 +62,6 @@
 {
 	lock((Lock*)&lk->access_lock);
 }
-	__isthreaded = 1;
 
 /*
  * sleep and wakeup
@@ -351,6 +342,46 @@
 void
 _pthreadinit(void)
 {
+	__isthreaded = 1;
 	signal(SIGUSR2, sigusr2handler);
 }
 
+/*
+ * FreeBSD 4 and earlier needs the context functions.
+ */
+void
+makecontext(ucontext_t *ucp, void (*func)(void), int argc, ...)
+{
+	int *sp;
+
+	sp = (int*)ucp->uc_stack.ss_sp+ucp->uc_stack.ss_size/4;
+	sp -= argc;
+	memmove(sp, &argc+1, argc*sizeof(int));
+	*--sp = 0;		/* return address */
+	ucp->uc_mcontext.mc_eip = (long)func;
+	ucp->uc_mcontext.mc_esp = (int)sp;
+}
+
+extern int getmcontext(mcontext_t*);
+extern int setmcontext(mcontext_t*);
+
+int
+getcontext(ucontext_t *uc)
+{
+	return getmcontext(&uc->uc_mcontext);
+}
+
+void
+setcontext(ucontext_t *uc)
+{
+	setmcontext(&uc->uc_mcontext);
+}
+
+int
+swapcontext(ucontext_t *oucp, ucontext_t *ucp)
+{
+	if(getcontext(oucp) == 0)
+		setcontext(ucp);
+	return 0;
+}
+