diff --git a/src/deh_lua.c b/src/deh_lua.c
index f131617c6..b3ad0f1c5 100644
--- a/src/deh_lua.c
+++ b/src/deh_lua.c
@@ -41,6 +41,11 @@ static inline int lib_freeslot(lua_State *L)
 	if (!lua_lumploading)
 		return luaL_error(L, "This function cannot be called from within a hook or coroutine!");
 
+	if (!deh_loaded)
+		initfreeslots();
+
+	deh_loaded = true;
+
 	while (n-- > 0)
 	{
 		s = Z_StrDup(luaL_checkstring(L,1));