diff --git a/lapi.c b/lapi.c
index 3c620d4b..3876956d 100644
--- a/lapi.c
+++ b/lapi.c
@@ -1163,7 +1163,7 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
     }
     case LUA_GCSTEP: {
       int data = va_arg(argp, int);
-      l_mem debt = 1;  /* =1 to signal that it did an actual step */
+      l_obj debt = 1;  /* =1 to signal that it did an actual step */
       lu_byte oldstp = g->gcstp;
       g->gcstp = 0;  /* allow GC to run (GCSTPGC must be zero here) */
       if (data == 0) {
@@ -1217,8 +1217,8 @@ LUA_API int lua_gc (lua_State *L, int what, ...) {
       if (stepmul != 0)
         setgcparam(g->gcstepmul, stepmul);
       if (stepsize != 0)
-        g->gcstepsize = (stepsize <= log2maxs(l_mem)) ? stepsize
-                                                      : log2maxs(l_mem);
+        g->gcstepsize = (stepsize <= log2maxs(l_obj)) ? stepsize
+                                                      : log2maxs(l_obj);
       luaC_changemode(L, KGC_INC);
       break;
     }
diff --git a/lgc.c b/lgc.c
index 9c5cc2e3..0e4e5552 100644
--- a/lgc.c
+++ b/lgc.c
@@ -93,7 +93,7 @@
 #define markobjectN(g,t)	{ if (t) markobject(g,t); }
 
 static void reallymarkobject (global_State *g, GCObject *o);
-static l_mem atomic (lua_State *L);
+static l_obj atomic (lua_State *L);
 static void entersweep (lua_State *L);
 
 
@@ -335,9 +335,9 @@ static void markmt (global_State *g) {
 /*
 ** mark all objects in list of being-finalized
 */
-static l_mem markbeingfnz (global_State *g) {
+static l_obj markbeingfnz (global_State *g) {
   GCObject *o;
-  l_mem count = 0;
+  l_obj count = 0;
   for (o = g->tobefnz; o != NULL; o = o->next) {
     count++;
     markobject(g, o);
@@ -357,8 +357,8 @@ static l_mem markbeingfnz (global_State *g) {
 ** upvalues, as they have nothing to be checked. (If the thread gets an
 ** upvalue later, it will be linked in the list again.)
 */
-static l_mem remarkupvals (global_State *g) {
-  l_mem work = 0;
+static l_obj remarkupvals (global_State *g) {
+  l_obj work = 0;
   lua_State *thread;
   lua_State **p = &g->twups;
   while ((thread = *p) != NULL) {
@@ -662,8 +662,8 @@ static void propagatemark (global_State *g) {
 }
 
 
-static l_mem propagateall (global_State *g) {
-  l_mem work = 0;
+static l_obj propagateall (global_State *g) {
+  l_obj work = 0;
   while (g->gray) {
     propagatemark(g);
     work++;
@@ -678,9 +678,9 @@ static l_mem propagateall (global_State *g) {
 ** inverts the direction of the traversals, trying to speed up
 ** convergence on chains in the same table.
 */
-static l_mem convergeephemerons (global_State *g) {
+static l_obj convergeephemerons (global_State *g) {
   int changed;
-  l_mem work = 0;
+  l_obj work = 0;
   int dir = 0;
   do {
     GCObject *w;
@@ -715,8 +715,8 @@ static l_mem convergeephemerons (global_State *g) {
 /*
 ** clear entries with unmarked keys from all weaktables in list 'l'
 */
-static l_mem clearbykeys (global_State *g, GCObject *l) {
-  l_mem work = 0;
+static l_obj clearbykeys (global_State *g, GCObject *l) {
+  l_obj work = 0;
   for (; l; l = gco2t(l)->gclist) {
     Table *h = gco2t(l);
     Node *limit = gnodelast(h);
@@ -737,8 +737,8 @@ static l_mem clearbykeys (global_State *g, GCObject *l) {
 ** clear entries with unmarked values from all weaktables in list 'l' up
 ** to element 'f'
 */
-static l_mem clearbyvalues (global_State *g, GCObject *l, GCObject *f) {
-  l_mem work = 0;
+static l_obj clearbyvalues (global_State *g, GCObject *l, GCObject *f) {
+  l_obj work = 0;
   for (; l != f; l = gco2t(l)->gclist) {
     Table *h = gco2t(l);
     Node *n, *limit = gnodelast(h);
@@ -1054,7 +1054,7 @@ void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) {
 static void setpause (global_State *g) {
   unsigned int pause = getgcparam(g->gcpause);
   lu_mem threshold = g->marked / 8 * pause / 12;
-  l_mem debt = gettotalobjs(g) - threshold;
+  l_obj debt = gettotalobjs(g) - threshold;
   if (debt > 0) debt = 0;
   luaE_setdebt(g, debt);
 }
@@ -1306,7 +1306,7 @@ static void atomic2gen (lua_State *L, global_State *g) {
 ** total number of objects grows 'genminormul'%.
 */
 static void setminordebt (global_State *g) {
-  luaE_setdebt(g, -(cast(l_mem, (gettotalobjs(g) / 100)) * g->genminormul));
+  luaE_setdebt(g, -(cast(l_obj, (gettotalobjs(g) / 100)) * g->genminormul));
 }
 
 
@@ -1431,8 +1431,8 @@ static void genstep (lua_State *L, global_State *g) {
   if (g->lastatomic != 0)  /* last collection was a bad one? */
     stepgenfull(L, g);  /* do a full step */
   else {
-    l_mem majorbase = g->GCestimate;  /* objects after last major collection */
-    l_mem majorinc = (majorbase / 100) * getgcparam(g->genmajormul);
+    l_obj majorbase = g->GCestimate;  /* objects after last major collection */
+    l_obj majorinc = (majorbase / 100) * getgcparam(g->genmajormul);
     if (g->GCdebt > 0 && gettotalobjs(g) > majorbase + majorinc) {
       g->marked = 0;
       fullgen(L, g);  /* do a major collection */
@@ -1512,8 +1512,8 @@ void luaC_freeallobjects (lua_State *L) {
 }
 
 
-static l_mem atomic (lua_State *L) {
-  l_mem work = 0;
+static l_obj atomic (lua_State *L) {
+  l_obj work = 0;
   global_State *g = G(L);
   GCObject *origweak, *origall;
   GCObject *grayagain = g->grayagain;  /* save original list */
@@ -1558,7 +1558,7 @@ static l_mem atomic (lua_State *L) {
 static void sweepstep (lua_State *L, global_State *g,
                        int nextstate, GCObject **nextlist) {
   if (g->sweepgc) {
-    l_mem olddebt = g->GCdebt;
+    l_obj olddebt = g->GCdebt;
     g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX);
     g->GCestimate += g->GCdebt - olddebt;  /* update estimate */
   }
@@ -1569,9 +1569,9 @@ static void sweepstep (lua_State *L, global_State *g,
 }
 
 
-static l_mem singlestep (lua_State *L) {
+static l_obj singlestep (lua_State *L) {
   global_State *g = G(L);
-  l_mem work;
+  l_obj work;
   lua_assert(!g->gcstopem);  /* collector is not reentrant */
   g->gcstopem = 1;  /* no emergency collections while collecting */
   switch (g->gcstate) {
@@ -1658,10 +1658,10 @@ void luaC_runtilstate (lua_State *L, int statesmask) {
 */
 static void incstep (lua_State *L, global_State *g) {
   int stepmul = (getgcparam(g->gcstepmul) | 1);  /* avoid division by 0 */
-  l_mem debt = (g->GCdebt / 100) * stepmul;
-  l_mem stepsize = cast(l_mem, 1) << g->gcstepsize;
+  l_obj debt = (g->GCdebt / 100) * stepmul;
+  l_obj stepsize = cast(l_obj, 1) << g->gcstepsize;
   do {  /* repeat until pause or enough "credit" (negative debt) */
-    l_mem work = singlestep(L);  /* perform one single step */
+    l_obj work = singlestep(L);  /* perform one single step */
     debt -= work;
   } while (debt > -stepsize && g->gcstate != GCSpause);
   if (g->gcstate == GCSpause)
diff --git a/llimits.h b/llimits.h
index ef108f5f..525b3647 100644
--- a/llimits.h
+++ b/llimits.h
@@ -16,19 +16,21 @@
 
 
 /*
-** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count
-** the total memory used by Lua (in bytes). Usually, 'size_t' and
+** 'lu_mem' is an unsigned integer big enough to count the total memory
+** used by Lua (in bytes). 'l_obj' is a signed integer big enough to
+** count the total number of objects used by Lua. (It is negative due
+** to the use of debt in several computations.)  Usually, 'size_t' and
 ** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines.
 */
 #if defined(LUAI_MEM)		/* { external definitions? */
 typedef LUAI_UMEM lu_mem;
-typedef LUAI_MEM l_mem;
+typedef LUAI_MEM l_obj;
 #elif LUAI_IS32INT	/* }{ */
 typedef size_t lu_mem;
-typedef ptrdiff_t l_mem;
+typedef ptrdiff_t l_obj;
 #else  /* 16-bit ints */	/* }{ */
 typedef unsigned long lu_mem;
-typedef long l_mem;
+typedef long l_obj;
 #endif				/* } */
 
 
@@ -47,7 +49,7 @@ typedef signed char ls_byte;
 
 #define MAX_LUMEM	((lu_mem)(~(lu_mem)0))
 
-#define MAX_LMEM	((l_mem)(MAX_LUMEM >> 1))
+#define MAX_LMEM	((l_obj)(MAX_LUMEM >> 1))
 
 
 #define MAX_INT		INT_MAX  /* maximum value of an int */
diff --git a/lstate.c b/lstate.c
index 9f615342..01393c41 100644
--- a/lstate.c
+++ b/lstate.c
@@ -86,8 +86,8 @@ static unsigned int luai_makeseed (lua_State *L) {
 ** set GCdebt to a new value keeping the value (totalobjs + GCdebt)
 ** invariant (and avoiding underflows in 'totalobjs')
 */
-void luaE_setdebt (global_State *g, l_mem debt) {
-  l_mem tb = gettotalobjs(g);
+void luaE_setdebt (global_State *g, l_obj debt) {
+  l_obj tb = gettotalobjs(g);
   lua_assert(tb > 0);
   if (debt < tb - MAX_LMEM)
     debt = tb - MAX_LMEM;  /* will make 'totalobjs == MAX_LMEM' */
diff --git a/lstate.h b/lstate.h
index 3ffd09b7..240550c2 100644
--- a/lstate.h
+++ b/lstate.h
@@ -249,10 +249,10 @@ typedef struct CallInfo {
 typedef struct global_State {
   lua_Alloc frealloc;  /* function to reallocate memory */
   void *ud;         /* auxiliary data to 'frealloc' */
-  l_mem totalbytes;  /* number of bytes currently allocated */
-  l_mem totalobjs;  /* total number of objects allocated - GCdebt */
-  l_mem GCdebt;  /* bytes allocated not yet compensated by the collector */
-  lu_mem marked;  /* number of objects marked in a GC cycle */
+  lu_mem totalbytes;  /* number of bytes currently allocated */
+  l_obj totalobjs;  /* total number of objects allocated - GCdebt */
+  l_obj GCdebt;  /* bytes allocated not yet compensated by the collector */
+  l_obj marked;  /* number of objects marked in a GC cycle */
   lu_mem GCestimate;  /* an estimate of the non-garbage memory in use */
   lu_mem lastatomic;  /* see function 'genstep' in file 'lgc.c' */
   stringtable strt;  /* hash table for strings */
@@ -391,7 +391,7 @@ union GCUnion {
 #define gettotalobjs(g)	((g)->totalobjs + (g)->GCdebt)
 
 
-LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt);
+LUAI_FUNC void luaE_setdebt (global_State *g, l_obj debt);
 LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1);
 LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L);
 LUAI_FUNC void luaE_freeCI (lua_State *L);
diff --git a/ltests.c b/ltests.c
index 57530884..cc4bf58f 100644
--- a/ltests.c
+++ b/ltests.c
@@ -531,7 +531,7 @@ static void checkobject (global_State *g, GCObject *o, int maybedead,
 }
 
 
-static lu_mem checkgraylist (global_State *g, GCObject *o) {
+static l_obj checkgraylist (global_State *g, GCObject *o) {
   int total = 0;  /* count number of elements in the list */
   cast_void(g);  /* better to keep it if we need to print an object */
   while (o) {
@@ -560,7 +560,7 @@ static lu_mem checkgraylist (global_State *g, GCObject *o) {
 /*
 ** Check objects in gray lists.
 */
-static lu_mem checkgrays (global_State *g) {
+static l_obj checkgrays (global_State *g) {
   int total = 0;  /* count number of elements in all lists */
   if (!keepinvariant(g)) return total;
   total += checkgraylist(g, g->gray);
@@ -577,7 +577,7 @@ static lu_mem checkgrays (global_State *g) {
 ** 'count' and check its TESTBIT. (It must have been previously set by
 ** 'checkgraylist'.)
 */
-static void incifingray (global_State *g, GCObject *o, lu_mem *count) {
+static void incifingray (global_State *g, GCObject *o, l_obj *count) {
   if (!keepinvariant(g))
     return;  /* gray lists not being kept in these phases */
   if (o->tt == LUA_VUPVAL) {
@@ -594,10 +594,10 @@ static void incifingray (global_State *g, GCObject *o, lu_mem *count) {
 }
 
 
-static lu_mem checklist (global_State *g, int maybedead, int tof,
+static l_obj checklist (global_State *g, int maybedead, int tof,
   GCObject *newl, GCObject *survival, GCObject *old, GCObject *reallyold) {
   GCObject *o;
-  lu_mem total = 0;  /* number of object that should be in  gray lists */
+  l_obj total = 0;  /* number of object that should be in  gray lists */
   for (o = newl; o != survival; o = o->next) {
     checkobject(g, o, maybedead, G_NEW);
     incifingray(g, o, &total);
@@ -626,8 +626,8 @@ int lua_checkmemory (lua_State *L) {
   global_State *g = G(L);
   GCObject *o;
   int maybedead;
-  lu_mem totalin;  /* total of objects that are in gray lists */
-  lu_mem totalshould;  /* total of objects that should be in gray lists */
+  l_obj totalin;  /* total of objects that are in gray lists */
+  l_obj totalshould;  /* total of objects that should be in gray lists */
   if (keepinvariant(g)) {
     assert(!iswhite(g->mainthread));
     assert(!iswhite(gcvalue(&g->l_registry)));
@@ -1033,7 +1033,7 @@ static int query_inc (lua_State *L) {
   lua_pushinteger(L, g->GCdebt);
   lua_pushinteger(L, getgcparam(g->gcpause));
   lua_pushinteger(L, getgcparam(g->gcstepmul));
-  lua_pushinteger(L, cast(l_mem, 1) << g->gcstepsize);
+  lua_pushinteger(L, cast(l_obj, 1) << g->gcstepsize);
   return 5;
 }