diff --git a/src/GNUmakefile b/src/GNUmakefile
index c426b02..1f0dd7d 100644
--- a/src/GNUmakefile
+++ b/src/GNUmakefile
@@ -22,7 +22,7 @@ VENDOR_$(d) = $(or $(CQUEUES_VENDOR),$(shell $(<D)/../mk/changelog author))
 VERSION_$(d) = $(or $(CQUEUES_VERSION),$(shell $(<D)/../mk/changelog version))
 COMMIT_$(d) = $(shell $(<D)/../mk/changelog commit)
 
-CPPFLAGS_$(d) = $(ALL_CPPFLAGS)
+CPPFLAGS_$(d) = $(ALL_CPPFLAGS) -DCOMPAT53_PREFIX=cqueues
 CFLAGS_$(d) = $(ALL_CFLAGS)
 SOFLAGS_$(d) = $(ALL_SOFLAGS)
 LDFLAGS_$(d) = $(ALL_LDFLAGS)
@@ -50,7 +50,7 @@ define BUILD_$(d)
 $$(d)/$(1)/cqueues.so: $$(addprefix $$(d)/$(1)/, $$(OBJS_$(d))) $$(d)/lib/libnonlua.a
 	$$(CC) -o $$@ $$^ $$(SOFLAGS_$$(abspath $$(@D)/..)) $$(LDFLAGS_$$(abspath $$(@D)/..)) $$(LIBS_$$(abspath $$(@D)/..))
 
-$$(d)/$(1)/%.o: $$(d)/%.c $$(d)/cqueues.h $$(d)/compat52.h $$(d)/config.h
+$$(d)/$(1)/%.o: $$(d)/%.c $$(d)/cqueues.h $$(d)/../vendor/compat53/c-api/compat-5.3.h $$(d)/config.h
 	$$(MKDIR) -p $$(@D)
 	$$(CC) $$(CFLAGS_$$(<D)) $$(ALL_LUA$(subst .,,$(1))_CPPFLAGS) $$(CPPFLAGS_$$(<D)) -c -o $$@ $$<
 
@@ -66,6 +66,14 @@ $$(d)/$(1)/thread.o: $$(d)/lib/llrb.h
 
 $$(d)/$(1)/notify.o: $$(d)/lib/notify.h
 
+ifneq ($(1), 5.3)
+$$(d)/$(1)/compat53.o: $$(d)/../vendor/compat53/c-api/compat-5.3.c $$(d)/../vendor/compat53/c-api/compat-5.3.h $$(d)/config.h
+	$$(MKDIR) -p $$(@D)
+	$$(CC) $$(CFLAGS_$(d)) $$(ALL_LUA$(subst .,,$(1))_CPPFLAGS) $$(CPPFLAGS_$(d)) -c -o $$@ $$<
+
+$$(d)/$(1)/cqueues.so: $$(d)/$(1)/compat53.o
+endif
+
 .SECONDARY: liblua$(1)-cqueues cqueues$(1) cqueues
 
 liblua$(1)-cqueues cqueues$(1) cqueues: $$(d)/$(1)/cqueues.so
diff --git a/src/compat52.h b/src/compat52.h
deleted file mode 100644
index c66c310..0000000
--- a/src/compat52.h
+++ /dev/null
@@ -1,166 +0,0 @@
-/* ==========================================================================
- * compat52.h - Routines for Lua 5.2 compatibility
- * --------------------------------------------------------------------------
- * Copyright (c) 2012  William Ahern
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sublicense, and/or sell copies of the Software, and to permit
- * persons to whom the Software is furnished to do so, subject to the
- * following conditions:
- *
- * The above copyright notice and this permission notice shall be included
- * in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
- * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
- * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
- * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
- * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
- * USE OR OTHER DEALINGS IN THE SOFTWARE.
- * ==========================================================================
- */
-#if LUA_VERSION_NUM < 502
-
-#define LUA_OK 0
-
-
-static void luaL_setmetatable(lua_State *L, const char *tname) {
-	luaL_getmetatable(L, tname);
-	lua_setmetatable(L, -2);
-} /* luaL_setmetatable() */
-
-
-static int lua_absindex(lua_State *L, int idx) {
-	return (idx > 0 || idx <= LUA_REGISTRYINDEX)? idx : lua_gettop(L) + idx + 1;
-} /* lua_absindex() */
-
-
-static void *luaL_testudata(lua_State *L, int arg, const char *tname) {
-	void *p = lua_touserdata(L, arg);
-	int eq;
-
-	if (!p || !lua_getmetatable(L, arg))
-		return 0;
-
-	luaL_getmetatable(L, tname);
-	eq = lua_rawequal(L, -2, -1);
-	lua_pop(L, 2);
-
-	return (eq)? p : 0;
-} /* luaL_testudate() */
-
-
-static void luaL_setfuncs(lua_State *L, const luaL_Reg *l, int nup) {
-	int i, t = lua_absindex(L, -1 - nup);
-
-	for (; l->name; l++) {
-		for (i = 0; i < nup; i++)
-			lua_pushvalue(L, -nup);
-		lua_pushcclosure(L, l->func, nup);
-		lua_setfield(L, t, l->name);
-	}
-
-	lua_pop(L, nup);
-} /* luaL_setfuncs() */
-
-
-#define luaL_newlibtable(L, l) \
-	lua_createtable(L, 0, (sizeof (l) / sizeof *(l)) - 1)
-
-#define luaL_newlib(L, l) \
-	(luaL_newlibtable((L), (l)), luaL_setfuncs((L), (l), 0))
-
-
-static int luaL_getsubtable(lua_State *L, int index, const char *tname) {
-	lua_getfield(L, index, tname);
-
-	if (lua_istable(L, -1))
-		return 1;
-
-	lua_pop(L, 1);
-	index = lua_absindex(L, index);
-	lua_newtable(L);
-	lua_pushvalue(L, -1);
-	lua_setfield(L, index, tname);
-
-	return 0;
-} /* luaL_getsubtable() */
-
-
-static void luaL_requiref(lua_State *L, const char *modname, lua_CFunction openf, int glb) {
-	lua_pushcfunction(L, openf);
-	lua_pushstring(L, modname);
-	lua_call(L, 1, 1);
-
-	luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED");
-	lua_pushvalue(L, -2);
-	lua_setfield(L, -2, modname);
-	lua_pop(L, 1);
-
-	if (glb) {
-		lua_pushvalue(L, -1);
-		lua_setglobal(L, modname);
-	}
-} /* luaL_requiref() */
-
-
-#define lua_resume(L, from, nargs) lua_resume((L), (nargs))
-
-
-static void lua_rawgetp(lua_State *L, int index, const void *p) {
-	index = lua_absindex(L, index);
-	lua_pushlightuserdata(L, (void *)p);
-	lua_rawget(L, index);
-} /* lua_rawgetp() */
-
-static void lua_rawsetp(lua_State *L, int index, const void *p) {
-	index = lua_absindex(L, index);
-	lua_pushlightuserdata(L, (void *)p);
-	lua_pushvalue(L, -2);
-	lua_rawset(L, index);
-	lua_pop(L, 1);
-} /* lua_rawsetp() */
-
-
-#ifndef LUA_UNSIGNED
-#define LUA_UNSIGNED unsigned
-#endif
-
-typedef LUA_UNSIGNED lua_Unsigned;
-
-
-static void lua_pushunsigned(lua_State *L, lua_Unsigned n) {
-	lua_pushnumber(L, (lua_Number)n);
-} /* lua_pushunsigned() */
-
-static lua_Unsigned luaL_checkunsigned(lua_State *L, int arg) {
-	return (lua_Unsigned)luaL_checknumber(L, arg);
-} /* luaL_checkunsigned() */
-
-
-static lua_Unsigned luaL_optunsigned(lua_State *L, int arg, lua_Unsigned def) {
-	return (lua_Unsigned)luaL_optnumber(L, arg, (lua_Number)def);
-} /* luaL_optunsigned() */
-
-
-#ifndef LUA_FILEHANDLE /* Not defined by earlier LuaJIT releases */
-#define LUA_FILEHANDLE "FILE*"
-#endif
-
-/*
- * Lua 5.1 userdata is a simple FILE *, while LuaJIT is a struct with the
- * first member a FILE *, similar to Lua 5.2.
- */
-typedef struct luaL_Stream {
-	FILE *f;
-} luaL_Stream;
-
-
-#define lua_rawlen(...) lua_objlen(__VA_ARGS__)
-
-
-#endif /* LUA_VERSION_NUM < 502 */
diff --git a/src/cqueues.c b/src/cqueues.c
index d452640..6528706 100644
--- a/src/cqueues.c
+++ b/src/cqueues.c
@@ -810,12 +810,7 @@ static int kpoll_wait(struct kpoll *kp, double timeout) {
  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
 
 #if LUA_VERSION_NUM >= 502
-
-#if LUA_VERSION_NUM >= 503
-static int auxlib_tostringk(lua_State *L NOTUSED, int status NOTUSED, lua_KContext ctx NOTUSED) {
-#else
-static int auxlib_tostringk(lua_State *L NOTUSED) {
-#endif
+LUA_KFUNCTION(auxlib_tostringk) {
 	if (luaL_getmetafield(L, 1, "__tostring")) {
 		lua_pushfstring(L, "%s: %p", luaL_typename(L, 1), lua_topointer(L, 1));
 	} else {
@@ -833,11 +828,7 @@ static int auxlib_tostring(lua_State *L) {
 		lua_settop(L, 2);
 		lua_callk(L, 1, 1, 0, &auxlib_tostringk);
 
-#if LUA_VERSION_NUM >= 503
 		return auxlib_tostringk(L, LUA_OK, 0);
-#else
-		return auxlib_tostringk(L);
-#endif
 	} else {
 		luaL_tolstring(L, 1, NULL);
 
@@ -2199,10 +2190,10 @@ static double cqueue_timeout_(struct cqueue *Q) {
 } /* cqueue_timeout_() */
 
 
-#if LUA_VERSION_NUM <= 502
-static int cqueue_step_cont(lua_State *L) {
+#if LUA_VERSION_NUM >= 502
+LUA_KFUNCTION(cqueue_step_cont) {
 #else
-static int cqueue_step_cont(lua_State *L, int status NOTUSED, lua_KContext ctx NOTUSED) {
+static int cqueue_step_cont(lua_State *L) {
 #endif
 	int nargs = lua_gettop(L);
 	struct callinfo I = CALLINFO_INITIALIZER;
diff --git a/src/cqueues.h b/src/cqueues.h
index d289324..0e3303e 100644
--- a/src/cqueues.h
+++ b/src/cqueues.h
@@ -40,9 +40,7 @@
 #include <lualib.h>
 #include <lauxlib.h>
 
-#if LUA_VERSION_NUM < 502
-#include "compat52.h"
-#endif
+#include "../vendor/compat53/c-api/compat-5.3.h"
 
 
 /*
diff --git a/src/thread.c b/src/thread.c
index a46a1bd..65d7fb8 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -498,11 +498,7 @@ static int ct_setfarg(lua_State *L, struct cthread *ct, struct cthread_arg *arg,
 		T = lua_newthread(L);
 		luaL_buffinit(T, &B);
 		lua_pushvalue(L, index);
-#if LUA_VERSION_NUM >= 503
 		lua_dump(L, &dump_add, &B, 0);
-#else
-		lua_dump(L, &dump_add, &B);
-#endif
 		luaL_pushresult(&B);
 
 		arg->v.string.iov_base = (char *)luaL_checklstring(T, -1, &arg->v.string.iov_len);