diff --git a/libc/bionic/pthread_internal.h b/libc/bionic/pthread_internal.h
index 316a14a..e34788b 100644
--- a/libc/bionic/pthread_internal.h
+++ b/libc/bionic/pthread_internal.h
@@ -42,7 +42,6 @@
     pid_t                       tid;
     bool                        allocated_on_heap;
     pthread_cond_t              join_cond;
-    int                         join_count;
     void*                       return_value;
     int                         internal_flags;
     __pthread_cleanup_t*        cleanup_stack;
@@ -64,9 +63,18 @@
 __LIBC_HIDDEN__ void pthread_key_clean_all(void);
 __LIBC_HIDDEN__ void _pthread_internal_remove_locked(pthread_internal_t* thread);
 
+/* Has the thread been detached by a pthread_join or pthread_detach call? */
 #define PTHREAD_ATTR_FLAG_DETACHED      0x00000001
+
+/* Was the thread's stack allocated by the user rather than by us? */
 #define PTHREAD_ATTR_FLAG_USER_STACK    0x00000002
 
+/* Has the thread been joined by another thread? */
+#define PTHREAD_ATTR_FLAG_JOINED        0x00000004
+
+/* Has the thread already exited but not been joined? */
+#define PTHREAD_ATTR_FLAG_ZOMBIE        0x00000008
+
 __LIBC_HIDDEN__ extern pthread_internal_t* gThreadList;
 __LIBC_HIDDEN__ extern pthread_mutex_t gThreadListLock;