diff --git a/src/Main.cc b/src/Main.cc
index 415b0bd2..0fc9ade8 100644
--- a/src/Main.cc
+++ b/src/Main.cc
@@ -89,7 +89,7 @@ void drop_privileges(const string& username) {
   config_log.info("Switched to user %s (%d:%d)", username.c_str(), pw->pw_uid, pw->pw_gid);
 }
 
-Version get_cli_version(Arguments& args) {
+Version get_cli_version(Arguments& args, Version default_value = Version::UNKNOWN) {
   if (args.get<bool>("pc-patch")) {
     return Version::PC_PATCH;
   } else if (args.get<bool>("bb-patch")) {
@@ -118,6 +118,8 @@ Version get_cli_version(Arguments& args) {
     return Version::GC_EP3;
   } else if (args.get<bool>("bb")) {
     return Version::BB_V4;
+  } else if (default_value != Version::UNKNOWN) {
+    return default_value;
   } else {
     throw runtime_error("a version option is required");
   }
@@ -1313,7 +1315,8 @@ Action a_convert_rare_item_set(
         string data = rs->serialize_gsl(true);
         write_output_data(args, data.data(), data.size(), nullptr);
       } else if (ends_with(output_filename, ".afs")) {
-        string data = rs->serialize_afs();
+        bool is_v1 = ::is_v1(get_cli_version(args, Version::GC_V3));
+        string data = rs->serialize_afs(is_v1);
         write_output_data(args, data.data(), data.size(), nullptr);
       } else {
         throw runtime_error("cannot determine output format; use a filename ending with .json, .gsl, .gslb, or .afs");
diff --git a/src/RareItemSet.cc b/src/RareItemSet.cc
index 317f9556..29ad4d01 100644
--- a/src/RareItemSet.cc
+++ b/src/RareItemSet.cc
@@ -115,7 +115,7 @@ void RareItemSet::ParsedRELData::parse_t(StringReader r, bool is_v1) {
 }
 
 template <bool IsBigEndian>
-std::string RareItemSet::ParsedRELData::serialize_t() const {
+std::string RareItemSet::ParsedRELData::serialize_t(bool is_v1) const {
   using U32T = typename std::conditional<IsBigEndian, be_uint32_t, le_uint32_t>::type;
   using U16T = typename std::conditional<IsBigEndian, be_uint16_t, le_uint16_t>::type;
 
@@ -129,7 +129,7 @@ std::string RareItemSet::ParsedRELData::serialize_t() const {
   for (const auto& drop : this->monster_rares) {
     w.put(PackedDrop(drop));
   }
-  while (w.size() < root.monster_rares_offset + 0x65 * sizeof(PackedDrop)) {
+  while (w.size() < root.monster_rares_offset + (is_v1 ? 0x33 : 0x65) * sizeof(PackedDrop)) {
     w.put(empty_drop);
   }
   root.box_areas_offset = w.size();
@@ -198,11 +198,11 @@ RareItemSet::ParsedRELData::ParsedRELData(const SpecCollection& collection) {
   }
 }
 
-std::string RareItemSet::ParsedRELData::serialize(bool big_endian) const {
+std::string RareItemSet::ParsedRELData::serialize(bool big_endian, bool is_v1) const {
   if (big_endian) {
-    return this->serialize_t<true>();
+    return this->serialize_t<true>(is_v1);
   } else {
-    return this->serialize_t<false>();
+    return this->serialize_t<false>(is_v1);
   }
 }
 
@@ -378,12 +378,12 @@ RareItemSet::RareItemSet(const JSON& json, Version version, shared_ptr<const Ite
   }
 }
 
-std::string RareItemSet::serialize_afs() const {
+std::string RareItemSet::serialize_afs(bool is_v1) const {
   vector<string> files;
   for (uint8_t difficulty = 0; difficulty < 4; difficulty++) {
     for (uint8_t section_id = 0; section_id < 10; section_id++) {
       ParsedRELData rel(this->get_collection(GameMode::NORMAL, Episode::EP1, difficulty, section_id));
-      files.emplace_back(rel.serialize(false));
+      files.emplace_back(rel.serialize(false, is_v1));
     }
   }
   return AFSArchive::generate(files, false);
@@ -399,7 +399,7 @@ std::string RareItemSet::serialize_gsl(bool big_endian) const {
         try {
           string filename = this->gsl_entry_name_for_table(GameMode::NORMAL, episode, difficulty, section_id);
           ParsedRELData rel(this->get_collection(GameMode::NORMAL, episode, difficulty, section_id));
-          files.emplace(filename, rel.serialize(big_endian));
+          files.emplace(filename, rel.serialize(big_endian, false));
         } catch (const out_of_range&) {
           // Collection does not exist; skip it
         }
@@ -412,7 +412,7 @@ std::string RareItemSet::serialize_gsl(bool big_endian) const {
       try {
         string filename = this->gsl_entry_name_for_table(GameMode::CHALLENGE, Episode::EP1, difficulty, section_id);
         ParsedRELData rel(this->get_collection(GameMode::CHALLENGE, Episode::EP1, difficulty, section_id));
-        files.emplace(filename, rel.serialize(big_endian));
+        files.emplace(filename, rel.serialize(big_endian, false));
       } catch (const out_of_range&) {
         // Collection does not exist; skip it
       }
diff --git a/src/RareItemSet.hh b/src/RareItemSet.hh
index 8570516d..ac3d6ab5 100644
--- a/src/RareItemSet.hh
+++ b/src/RareItemSet.hh
@@ -35,7 +35,7 @@ public:
   std::vector<ExpandedDrop> get_enemy_specs(GameMode mode, Episode episode, uint8_t difficulty, uint8_t secid, uint8_t rt_index) const;
   std::vector<ExpandedDrop> get_box_specs(GameMode mode, Episode episode, uint8_t difficulty, uint8_t secid, uint8_t area) const;
 
-  std::string serialize_afs() const;
+  std::string serialize_afs(bool is_v1) const;
   std::string serialize_gsl(bool big_endian) const;
   std::string serialize_json(Version version, std::shared_ptr<const ItemNameIndex> name_index = nullptr) const;
 
@@ -86,12 +86,12 @@ protected:
     ParsedRELData() = default;
     ParsedRELData(StringReader r, bool big_endian, bool is_v1);
     explicit ParsedRELData(const SpecCollection& collection);
-    std::string serialize(bool big_endian) const;
+    std::string serialize(bool big_endian, bool is_v1) const;
 
     template <bool IsBigEndian>
     void parse_t(StringReader r, bool is_v1);
     template <bool IsBigEndian>
-    std::string serialize_t() const;
+    std::string serialize_t(bool is_v1) const;
 
     SpecCollection as_collection() const;
   };