diff --git a/src/Client.cc b/src/Client.cc
index b536894e..164f24a2 100644
--- a/src/Client.cc
+++ b/src/Client.cc
@@ -36,7 +36,7 @@ bool Client::send(string&& data) {
   }
 
   if (this->crypt_out.get()) {
-    this->crypt_out->encrypt(const_cast<char*>(data.data()), data.size());
+    this->crypt_out->encrypt(data.data(), data.size());
   }
 
   struct evbuffer* buf = bufferevent_get_output(this->bev);
diff --git a/src/ProxyServer.cc b/src/ProxyServer.cc
index ca807c96..d2950e44 100644
--- a/src/ProxyServer.cc
+++ b/src/ProxyServer.cc
@@ -67,7 +67,7 @@ void ProxyServer::send_to_end(const std::string& data, bool to_server) {
   PSOEncryption* crypt = to_server ? this->server_output_crypt.get() : this->client_output_crypt.get();
   if (crypt) {
     string crypted_data = data;
-    crypt->encrypt(const_cast<char*>(crypted_data.data()), crypted_data.size());
+    crypt->encrypt(crypted_data.data(), crypted_data.size());
     evbuffer_add(buf, crypted_data.data(), crypted_data.size());
   } else {
     evbuffer_add(buf, data.data(), data.size());
@@ -274,21 +274,19 @@ void ProxyServer::receive_and_process_commands(bool from_server) {
     }
 
     string command(command_size, '\0');
-    ssize_t bytes = evbuffer_remove(source_buf,
-        const_cast<char*>(command.data()), command_size);
+    ssize_t bytes = evbuffer_remove(source_buf, command.data(), command_size);
     if (bytes < static_cast<ssize_t>(command_size)) {
       throw logic_error("enough bytes available, but could not remove them");
     }
     //log(INFO, "[ProxyServer-debug] read command (%zX bytes)", bytes);
     // overwrite the header with the already-decrypted header
-    memcpy(const_cast<char*>(command.data()), input_header, this->header_size);
+    memcpy(command.data(), input_header, this->header_size);
 
     //log(INFO, "[ProxyServer-debug] received encrypted command with pre-decrypted header");
     //print_data(stderr, command);
 
     if (source_crypt) {
-      source_crypt->decrypt(
-          const_cast<char*>(command.data() + this->header_size),
+      source_crypt->decrypt(command.data() + this->header_size,
           command_size - this->header_size);
     }
 
@@ -346,7 +344,7 @@ void ProxyServer::receive_and_process_commands(bool from_server) {
           }
 
           ReconnectCommandArgs* args = reinterpret_cast<ReconnectCommandArgs*>(
-              const_cast<char*>(command.data() + this->header_size));
+              command.data() + this->header_size);
           memset(&this->next_destination, 0, sizeof(this->next_destination));
           struct sockaddr_in* sin = reinterpret_cast<struct sockaddr_in*>(
               &this->next_destination);
@@ -378,7 +376,7 @@ void ProxyServer::receive_and_process_commands(bool from_server) {
     // reencrypt and forward the command
     if (dest_buf) {
       if (dest_crypt) {
-        dest_crypt->encrypt(const_cast<char*>(command.data()), command.size());
+        dest_crypt->encrypt(command.data(), command.size());
       }
       //log(INFO, "[ProxyServer-debug] sending encrypted command");
       //print_data(stderr, command);
diff --git a/src/ProxyShell.cc b/src/ProxyShell.cc
index 27bb46f8..0de56b6a 100644
--- a/src/ProxyShell.cc
+++ b/src/ProxyShell.cc
@@ -54,7 +54,7 @@ commands:\n\
     if (data.size() == 0) {
       throw invalid_argument("no data given");
     }
-    uint16_t* size_field = reinterpret_cast<uint16_t*>(const_cast<char*>(data.data() + 2));
+    uint16_t* size_field = reinterpret_cast<uint16_t*>(data.data() + 2);
     *size_field = data.size();
 
     log(INFO, "%s (from proxy):", to_client ? "server" : "client");
@@ -78,7 +78,7 @@ commands:\n\
     }
     data.push_back('\0');
     data.resize((data.size() + 3) & (~3));
-    uint16_t* size_field = reinterpret_cast<uint16_t*>(const_cast<char*>(data.data() + 2));
+    uint16_t* size_field = reinterpret_cast<uint16_t*>(data.data() + 2);
     *size_field = data.size();
 
     log(INFO, "client (from proxy):");
diff --git a/src/Quest.cc b/src/Quest.cc
index dd8d90ea..90fa4fd1 100644
--- a/src/Quest.cc
+++ b/src/Quest.cc
@@ -366,7 +366,7 @@ string Quest::decode_gci(const string& filename) {
         "GCI file is truncated before download quest header (have 0x%zX bytes)", data.size()));
   }
   PSODownloadQuestHeader* h = reinterpret_cast<PSODownloadQuestHeader*>(
-      const_cast<char*>(data.data() + 0x2080));
+      data.data() + 0x2080);
   h->byteswap();
 
   string compressed_data_with_header = data.substr(0x2088, h->size);
@@ -385,8 +385,8 @@ string Quest::decode_gci(const string& filename) {
   if (compressed_data_with_header.size() < sizeof(DecryptedHeader)) {
     throw runtime_error("GCI file compressed data truncated during header");
   }
-  DecryptedHeader* dh = reinterpret_cast<DecryptedHeader*>(const_cast<char*>(
-      compressed_data_with_header.data()));
+  DecryptedHeader* dh = reinterpret_cast<DecryptedHeader*>(
+      compressed_data_with_header.data());
   if (dh->unknown1 || dh->unknown2 || dh->unknown4) {
     throw runtime_error("GCI file appears to be encrypted");
   }
@@ -476,8 +476,7 @@ vector<shared_ptr<const Quest>> QuestIndex::filter(GameVersion version,
 static string create_download_quest_file(const string& compressed_data,
     size_t decompressed_size) {
   string data(8, '\0');
-  auto* header = reinterpret_cast<PSODownloadQuestHeader*>(const_cast<char*>(
-      compressed_data.data()));
+  auto* header = reinterpret_cast<PSODownloadQuestHeader*>(data.data());
   header->size = decompressed_size + sizeof(PSODownloadQuestHeader);
   header->encryption_seed = random_object<uint32_t>();
   data += compressed_data;
@@ -487,7 +486,7 @@ static string create_download_quest_file(const string& compressed_data,
 
   // TODO: for DC quests, do we use DC encryption?
   PSOPCEncryption encr(header->encryption_seed);
-  encr.encrypt(const_cast<char*>(data.data() + sizeof(PSODownloadQuestHeader)),
+  encr.encrypt(data.data() + sizeof(PSODownloadQuestHeader),
       data.size() - sizeof(PSODownloadQuestHeader));
   return data;
 }
@@ -498,7 +497,7 @@ shared_ptr<Quest> Quest::create_download_quest(const string& file_basename) cons
   }
 
   string decompressed_bin = prs_decompress(*this->bin_contents());
-  void* data_ptr = const_cast<char*>(decompressed_bin.data());
+  void* data_ptr = decompressed_bin.data();
   switch (this->version) {
     case GameVersion::DC:
       reinterpret_cast<PSOQuestHeaderDC*>(data_ptr)->is_download = 0x01;
diff --git a/src/ReceiveCommands.cc b/src/ReceiveCommands.cc
index 771aa323..a236e0f8 100644
--- a/src/ReceiveCommands.cc
+++ b/src/ReceiveCommands.cc
@@ -2220,27 +2220,27 @@ void process_command(shared_ptr<ServerState> s, shared_ptr<Client> c,
     if (c->version == GameVersion::BB) {
       data_to_print.resize(size + 8);
       PSOCommandHeaderBB* header = reinterpret_cast<PSOCommandHeaderBB*>(
-          const_cast<char*>(data_to_print.data()));
+          data_to_print.data());
       header->command = command;
       header->flag = flag;
       header->size = size + 8;
-      memcpy(const_cast<char*>(data_to_print.data() + 8), data, size);
+      memcpy(data_to_print.data() + 8, data, size);
     } else if (c->version == GameVersion::PC) {
       data_to_print.resize(size + 4);
       PSOCommandHeaderPC* header = reinterpret_cast<PSOCommandHeaderPC*>(
-          const_cast<char*>(data_to_print.data()));
+          data_to_print.data());
       header->command = command;
       header->flag = flag;
       header->size = size + 4;
-      memcpy(const_cast<char*>(data_to_print.data() + 4), data, size);
+      memcpy(data_to_print.data() + 4, data, size);
     } else { // DC/GC
       data_to_print.resize(size + 4);
       PSOCommandHeaderDCGC* header = reinterpret_cast<PSOCommandHeaderDCGC*>(
-          const_cast<char*>(data_to_print.data()));
+          data_to_print.data());
       header->command = command;
       header->flag = flag;
       header->size = size + 4;
-      memcpy(const_cast<char*>(data_to_print.data() + 4), data, size);
+      memcpy(data_to_print.data() + 4, data, size);
     }
     print_data(stderr, data_to_print);
   }
diff --git a/src/SendCommands.cc b/src/SendCommands.cc
index c5a7ef12..fe567872 100644
--- a/src/SendCommands.cc
+++ b/src/SendCommands.cc
@@ -360,8 +360,8 @@ void send_guild_card_chunk_bb(shared_ptr<Client> c, size_t chunk_index) {
   }
 
   string contents(8, '\0');
-  *reinterpret_cast<uint32_t*>(const_cast<char*>(contents.data())) = 0;
-  *reinterpret_cast<uint32_t*>(const_cast<char*>(contents.data() + 4)) = chunk_index;
+  *reinterpret_cast<uint32_t*>(contents.data()) = 0;
+  *reinterpret_cast<uint32_t*>(contents.data() + 4) = chunk_index;
   contents.append(reinterpret_cast<char*>(&c->player.guild_cards + chunk_offset),
       data_size);
 
@@ -469,7 +469,7 @@ static void send_large_message_pc_patch_bb(shared_ptr<Client> c, uint8_t command
   u16string data;
   if (include_header) {
     data.resize(sizeof(LargeMessageOptionalHeader) / sizeof(char16_t));
-    *reinterpret_cast<LargeMessageOptionalHeader*>(const_cast<char16_t*>(data.data())) =
+    *reinterpret_cast<LargeMessageOptionalHeader*>(data.data()) =
         {0, from_serial_number};
   }
   data += text;
@@ -483,7 +483,7 @@ static void send_large_message_dc_gc(shared_ptr<Client> c, uint8_t command,
   string data;
   if (include_header) {
     data.resize(sizeof(LargeMessageOptionalHeader) / sizeof(char));
-    *reinterpret_cast<LargeMessageOptionalHeader*>(const_cast<char*>(data.data())) =
+    *reinterpret_cast<LargeMessageOptionalHeader*>(data.data()) =
         {0, from_serial_number};
   }
   data += encode_sjis(text);
@@ -2025,7 +2025,7 @@ void send_ep3_card_list_update(shared_ptr<Client> c) {
   auto file_data = file_cache.get("system/ep3/cardupdate.mnr");
 
   string data("\0\0\0\0", 4);
-  *reinterpret_cast<uint32_t*>(const_cast<char*>(data.data())) = file_data->size();
+  *reinterpret_cast<uint32_t*>(data.data()) = file_data->size();
   data += *file_data;
   data.resize((data.size() + 3) & ~3);
 
@@ -2049,7 +2049,7 @@ void send_ep3_map_list(shared_ptr<Lobby> l) {
   auto file_data = file_cache.get("system/ep3/maplist.mnr");
 
   string data(16, '\0');
-  PSOSubcommand* subs = reinterpret_cast<PSOSubcommand*>(const_cast<char*>(data.data()));
+  PSOSubcommand* subs = reinterpret_cast<PSOSubcommand*>(data.data());
   subs[0].dword = 0x000000B6;
   subs[1].dword = (23 + file_data->size()) & 0xFFFFFFFC;
   subs[2].dword = 0x00000040;
@@ -2065,7 +2065,7 @@ void send_ep3_map_data(shared_ptr<Lobby> l, uint32_t map_id) {
   auto file_data = file_cache.get(filename);
 
   string data(12, '\0');
-  PSOSubcommand* subs = reinterpret_cast<PSOSubcommand*>(const_cast<char*>(data.data()));
+  PSOSubcommand* subs = reinterpret_cast<PSOSubcommand*>(data.data());
   subs[0].dword = 0x000000B6;
   subs[1].dword = (19 + file_data->size()) & 0xFFFFFFFC;
   subs[2].dword = 0x00000041;
@@ -2168,7 +2168,7 @@ void send_server_time(shared_ptr<Client> c) {
   gmtime_r(&t_secs, &t_parsed);
 
   string time_str(128, 0);
-  size_t len = strftime(const_cast<char*>(time_str.data()), time_str.size(),
+  size_t len = strftime(time_str.data(), time_str.size(),
       "%Y:%m:%d: %H:%M:%S.000", &t_parsed);
   if (len == 0) {
     throw runtime_error("format_time buffer too short");
diff --git a/src/Server.cc b/src/Server.cc
index 4f1c7b0a..f9557638 100644
--- a/src/Server.cc
+++ b/src/Server.cc
@@ -184,7 +184,7 @@ void Server::receive_and_process_commands(shared_ptr<Client> c) {
   size_t new_bytes = evbuffer_get_length(buf);
   new_bytes &= ~(header_size - 1); // only read in multiples of header_size
   c->recv_buffer.resize(existing_bytes + new_bytes);
-  void* recv_ptr = const_cast<char*>(c->recv_buffer.data() + existing_bytes);
+  void* recv_ptr = c->recv_buffer.data() + existing_bytes;
   if (evbuffer_remove(buf, recv_ptr, new_bytes) != static_cast<ssize_t>(new_bytes)) {
     throw runtime_error("some bytes could not be read from the receive buffer");
   }
diff --git a/src/Shell.cc b/src/Shell.cc
index 6228a4d9..c62d4151 100644
--- a/src/Shell.cc
+++ b/src/Shell.cc
@@ -57,7 +57,7 @@ void Shell::read_stdin() {
     }
 
     string command(2048, '\0');
-    if (!fgets(const_cast<char*>(command.data()), command.size(), stdin)) {
+    if (!fgets(command.data(), command.size(), stdin)) {
       if (!any_command_read) {
         // ctrl+d probably; we should exit
         fputc('\n', stderr);
diff --git a/src/Text.hh b/src/Text.hh
index 47848a9e..bd895c1e 100644
--- a/src/Text.hh
+++ b/src/Text.hh
@@ -72,6 +72,6 @@ size_t add_color_inplace(T* a) {
 
 template <typename T>
 void add_color_inplace(std::basic_string<T>& a, size_t header_bytes) {
-  size_t count = add_color_inplace(const_cast<T*>(a.data() + header_bytes));
+  size_t count = add_color_inplace(a.data() + header_bytes);
   a.resize(count + header_bytes);
 }