diff --git a/lpeg.c b/lpeg.c
index 0c7c107ac..2c34c6fe4 100644
--- a/lpeg.c
+++ b/lpeg.c
@@ -3340,8 +3340,8 @@ static struct luaL_Reg metareg[] = {
 };
 
 
-int luaopen_lpeg (lua_State *L);
-int luaopen_lpeg (lua_State *L) {
+LUALIB_API int luaopen_lpeg (lua_State *L);
+LUALIB_API int luaopen_lpeg (lua_State *L) {
   luaL_newmetatable(L, PATTERN_T);
   lua_pushnumber(L, MAXBACK);  /* initialize maximum backtracking */
   lua_setfield(L, LUA_REGISTRYINDEX, MAXSTACKIDX);