diff --git a/src/lapi.c b/src/lapi.c
index 5d5145d..3e3cb5e 100644
--- a/src/lapi.c
+++ b/src/lapi.c
@@ -145,7 +145,6 @@ LUA_API lua_State *lua_newthread (lua_State *L) {
   setthvalue(L, L->top, L1);
   api_incr_top(L);
   lua_unlock(L);
-  luai_userstatethread(L, L1);
   return L1;
 }
 
diff --git a/src/ldo.c b/src/ldo.c
index d1bf786..ffcb031 100644
--- a/src/ldo.c
+++ b/src/ldo.c
@@ -422,7 +422,6 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
       return resume_error(L, "cannot resume non-suspended coroutine");
   if (L->nCcalls >= LUAI_MAXCCALLS)
     return resume_error(L, "C stack overflow");
-  luai_userstateresume(L, nargs);
   lua_assert(L->errfunc == 0);
   L->baseCcalls = ++L->nCcalls;
   status = luaD_rawrunprotected(L, resume, L->top - nargs);
@@ -442,7 +441,6 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
 
 
 LUA_API int lua_yield (lua_State *L, int nresults) {
-  luai_userstateyield(L, nresults);
   lua_lock(L);
   if (L->nCcalls > L->baseCcalls)
     luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
diff --git a/src/lstate.c b/src/lstate.c
index cdcd669..b283d46 100644
--- a/src/lstate.c
+++ b/src/lstate.c
@@ -129,7 +129,6 @@ lua_State *luaE_newthread (lua_State *L) {
 void luaE_freethread (lua_State *L, lua_State *L1) {
   luaF_close(L1, L1->stack);  /* close all upvalues for this thread */
   lua_assert(L1->openupval == NULL);
-  luai_userstatefree(L1);
   freestack(L, L1);
   luaM_freemem(L, cast(lu_byte*, L1), sizeof(lua_State));
 }
@@ -179,8 +178,6 @@ LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) {
     close_state(L);
     L = NULL;
   }
-  else
-    luai_userstateopen(L);
   return L;
 }
 
@@ -203,7 +200,6 @@ LUA_API void lua_close (lua_State *L) {
     L->nCcalls = L->baseCcalls = 0;
   } while (luaD_rawrunprotected(L, callallgcTM, NULL) != 0);
   lua_assert(G(L)->tmudata == NULL);
-  luai_userstateclose(L);
   close_state(L);
 }
 
diff --git a/src/luaconf.h b/src/luaconf.h
index f24ed0e..613739a 100644
--- a/src/luaconf.h
+++ b/src/luaconf.h
@@ -664,19 +664,6 @@ union luai_Cast { double l_d; long l_l; };
 #endif
 
 
-/*
-@@ luai_userstate* allow user-specific actions on threads.
-** CHANGE them if you defined LUAI_EXTRASPACE and need to do something
-** extra when a thread is created/deleted/resumed/yielded.
-*/
-#define luai_userstateopen(L)		((void)L)
-#define luai_userstateclose(L)		((void)L)
-#define luai_userstatethread(L,L1)	((void)L)
-#define luai_userstatefree(L)		((void)L)
-#define luai_userstateresume(L,n)	((void)L)
-#define luai_userstateyield(L,n)	((void)L)
-
-
 /*
 @@ LUA_INTFRMLEN is the length modifier for integer conversions
 @* in 'string.format'.
diff --git a/src/notes b/src/notes
index 3977255..ff25625 100644
--- a/src/notes
+++ b/src/notes
@@ -8,6 +8,5 @@ lua_State:
   &{Value; int tt} stack, stack_last, base, top
 
 == todo stack
-eradicate LUAI_EXTRASPACE
 lua_newstate
 lua_State's stack