diff --git a/include/errno.h b/include/errno.h
index a87c0f4..3c6db71 100644
--- a/include/errno.h
+++ b/include/errno.h
@@ -11,6 +11,7 @@
 #define ENOTDIR		0xBAD7
 #define ENAMETOOLONG	0xBAD8
 #define ENOSYS		0xBAD9
+#define EAGAIN		0xBADA
 
 #endif /* __ERRNO_H__ */
 
diff --git a/include/pthread.h b/include/pthread.h
index 29e0bdf..7433701 100644
--- a/include/pthread.h
+++ b/include/pthread.h
@@ -2,12 +2,12 @@
 #ifndef __PTHREAD_H__
 #define __PTHREAD_H__
 
-typedef uint64_t pthread_t;
-typedef uint64_t pthread_attr_t;
-typedef uint64_t pthread_barrier_t;
-typedef uint64_t pthread_barrierattr_t;
-typedef uint64_t pthread_mutex_t;
-typedef uint64_t pthread_mutexattr_t;
+typedef struct pthread *pthread_t;
+typedef struct pthread_attr *pthread_attr_t;
+typedef struct pthread_barrier *pthread_barrier_t;
+typedef struct pthread_barrierattr *pthread_barrierattr_t;
+typedef struct pthread_mutex *pthread_mutex_t;
+typedef struct pthread_mutexattr *pthread_mutexattr_t;
 
 pthread_t pthread_self(void);
 int pthread_create(pthread_t *thread, const pthread_attr_t *attr,
diff --git a/lib/libc/posix/pthread.c b/lib/libc/posix/pthread.c
index a32af77..8b89873 100644
--- a/lib/libc/posix/pthread.c
+++ b/lib/libc/posix/pthread.c
@@ -1,34 +1,101 @@
 
 #include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
 
 #include <unistd.h>
+#include <errno.h>
 #include <pthread.h>
 
 #include <syscall.h>
+#include <sys/syscall.h>
+
+struct pthread_attr {
+    uint64_t	_unused;
+};
+
+struct pthread {
+    uint64_t	tid;
+    int		errno;
+
+    // Initialization
+    void	*(*entry)(void *);
+    void	*arg;
+
+    // Termination
+    void	*result;
+};
 
 pthread_t
 pthread_self(void)
 {
+    // XXX Implement
+    return NULL;
+}
+
+void
+pthreadCreateHelper(void *arg)
+{
+    struct pthread *thr = (struct pthread *)arg;
+
+    OSThreadExit((uint64_t)(thr->entry)(thr->arg));
 }
 
 int
 pthread_create(pthread_t *thread, const pthread_attr_t *attr,
 	       void *(*start_routine)(void *), void *arg)
 {
+    uint64_t status;
+    struct pthread *thr;
+
+    thr = malloc(sizeof(*thr));
+    if (!thr) {
+	return EAGAIN;
+    }
+
+    memset(thr, 0, sizeof(*thr));
+
+    thr->entry = start_routine;
+    thr->arg = arg;
+
+    status = OSThreadCreate((uintptr_t)&pthreadCreateHelper, (uint64_t)thr);
+    if (SYSCALL_ERRCODE(status) != 0) {
+	free(thr);
+	return SYSCALL_ERRCODE(status);
+    }
+
+    thr->tid = SYSCALL_VALUE(status);
+
+    *thread = thr;
+
+    return 0;
 }
 
 void
 pthread_exit(void *value_ptr)
 {
-    OSThreadExit(value_ptr);
+    struct pthread *thr = pthread_self();
+
+    thr->result = value_ptr;
+
+    OSThreadExit(0);
 }
 
 int
 pthread_join(pthread_t thread, void **value_ptr)
 {
-    uint64_t value = OSThreadWait(thread);
+    struct pthread *thr = thread;
+    uint64_t status = OSThreadWait(thr->tid);
+    if (status != 0) {
+	return status;
+    }
 
-    *value_ptr = (void *)value;
+    *value_ptr = (void *)thr->result;
+
+    // Cleanup
+    free(thr);
+
+    return 0;
 }
 
 void