diff --git a/src/Lobby.cc b/src/Lobby.cc
index ec4695de..4b20f6d0 100644
--- a/src/Lobby.cc
+++ b/src/Lobby.cc
@@ -270,14 +270,16 @@ shared_ptr<Map> Lobby::load_maps(
     shared_ptr<const Map::RareEnemyRates> rare_rates,
     shared_ptr<PSOLFGEncryption> random_crypt,
     shared_ptr<const VersionedQuest> vq) {
+  if (!vq->dat_contents_decompressed) {
+    throw runtime_error("quest does not have DAT data");
+  }
   auto map = make_shared<Map>(version, lobby_id, random_crypt);
-  auto dat_contents = prs_decompress(*vq->dat_contents);
   map->add_enemies_and_objects_from_quest_data(
       episode,
       difficulty,
       event,
-      dat_contents.data(),
-      dat_contents.size(),
+      vq->dat_contents_decompressed->data(),
+      vq->dat_contents_decompressed->size(),
       rare_rates);
   return map;
 }
diff --git a/src/Quest.cc b/src/Quest.cc
index fa97f3aa..03f74577 100644
--- a/src/Quest.cc
+++ b/src/Quest.cc
@@ -222,6 +222,10 @@ VersionedQuest::VersionedQuest(
       available_expression(available_expression),
       enabled_expression(enabled_expression) {
 
+  if (this->dat_contents) {
+    this->dat_contents_decompressed = make_shared<string>(prs_decompress(*this->dat_contents));
+  }
+
   auto bin_decompressed = prs_decompress(*this->bin_contents);
 
   switch (this->version) {
diff --git a/src/Quest.hh b/src/Quest.hh
index 864a35d0..ab88d4ac 100644
--- a/src/Quest.hh
+++ b/src/Quest.hh
@@ -68,6 +68,7 @@ struct VersionedQuest {
   std::string long_description;
   std::shared_ptr<const std::string> bin_contents;
   std::shared_ptr<const std::string> dat_contents;
+  std::shared_ptr<const std::string> dat_contents_decompressed;
   std::shared_ptr<const std::string> pvr_contents;
   std::shared_ptr<const BattleRules> battle_rules;
   ssize_t challenge_template_index;
diff --git a/src/ReceiveSubcommands.cc b/src/ReceiveSubcommands.cc
index b199e3ee..5170c012 100644
--- a/src/ReceiveSubcommands.cc
+++ b/src/ReceiveSubcommands.cc
@@ -3012,9 +3012,6 @@ static void on_battle_restart_bb(shared_ptr<Client> c, uint8_t, uint8_t, void* d
       l->leader_id == c->lobby_client_id) {
     const auto& cmd = check_size_t<G_StartBattle_BB_6xCF>(data, size);
 
-    auto vq = l->quest->version(Version::BB_V4, c->language());
-    auto dat_contents = prs_decompress(*vq->dat_contents);
-
     auto new_rules = make_shared<BattleRules>(cmd.rules);
     if (l->item_creator) {
       l->item_creator->set_restrictions(new_rules);