diff --git a/ext/socket/ipsocket.c b/ext/socket/ipsocket.c
index eff4278c4f568f..a034fe879b354c 100644
--- a/ext/socket/ipsocket.c
+++ b/ext/socket/ipsocket.c
@@ -23,8 +23,17 @@ struct inetsock_arg
     int type;
     VALUE resolv_timeout;
     VALUE connect_timeout;
+    VALUE open_timeout;
 };
 
+void
+rsock_raise_user_specified_timeout()
+{
+    VALUE errno_module = rb_const_get(rb_cObject, rb_intern("Errno"));
+    VALUE etimedout_error = rb_const_get(errno_module, rb_intern("ETIMEDOUT"));
+    rb_raise(etimedout_error, "user specified timeout");
+}
+
 static VALUE
 inetsock_cleanup(VALUE v)
 {
@@ -44,6 +53,13 @@ inetsock_cleanup(VALUE v)
     return Qnil;
 }
 
+static VALUE
+current_clocktime()
+{
+    VALUE clock_monotnic_const = rb_const_get(rb_mProcess, rb_intern("CLOCK_MONOTONIC"));
+    return rb_funcall(rb_mProcess, rb_intern("clock_gettime"), 1, clock_monotnic_const);
+}
+
 static VALUE
 init_inetsock_internal(VALUE v)
 {
@@ -56,13 +72,18 @@ init_inetsock_internal(VALUE v)
     const char *syscall = 0;
     VALUE resolv_timeout = arg->resolv_timeout;
     VALUE connect_timeout = arg->connect_timeout;
+    VALUE open_timeout = arg->open_timeout;
+    VALUE timeout;
+    VALUE starts_at;
+    unsigned int timeout_msec;
 
-    unsigned int t = NIL_P(resolv_timeout) ? 0 : rsock_value_timeout_to_msec(resolv_timeout);
+    timeout = NIL_P(open_timeout) ? resolv_timeout : open_timeout;
+    timeout_msec = NIL_P(timeout) ? 0 : rsock_value_timeout_to_msec(timeout);
+    starts_at = current_clocktime();
 
     arg->remote.res = rsock_addrinfo(arg->remote.host, arg->remote.serv,
                                      family, SOCK_STREAM,
-                                     (type == INET_SERVER) ? AI_PASSIVE : 0, t);
-
+                                     (type == INET_SERVER) ? AI_PASSIVE : 0, timeout_msec);
 
     /*
      * Maybe also accept a local address
@@ -125,8 +146,16 @@ init_inetsock_internal(VALUE v)
                 syscall = "bind(2)";
             }
 
+            if (NIL_P(open_timeout)) {
+                timeout = connect_timeout;
+            } else {
+                VALUE elapsed = rb_funcall(current_clocktime(), '-', 1, starts_at);
+                timeout = rb_funcall(open_timeout, '-', 1, elapsed);
+                if (rb_funcall(timeout, '<', 1, INT2FIX(0)) == Qtrue) rsock_raise_user_specified_timeout();
+            }
+
             if (status >= 0) {
-                status = rsock_connect(io, res->ai_addr, res->ai_addrlen, (type == INET_SOCKS), connect_timeout);
+                status = rsock_connect(io, res->ai_addr, res->ai_addrlen, (type == INET_SOCKS), timeout);
                 syscall = "connect(2)";
             }
         }
@@ -175,8 +204,16 @@ init_inetsock_internal(VALUE v)
 #if FAST_FALLBACK_INIT_INETSOCK_IMPL == 0
 
 VALUE
-rsock_init_inetsock(VALUE self, VALUE remote_host, VALUE remote_serv, VALUE local_host, VALUE local_serv, int type, VALUE resolv_timeout, VALUE connect_timeout, VALUE _fast_fallback, VALUE _test_mode_settings)
-{
+rsock_init_inetsock(
+    VALUE self, VALUE remote_host, VALUE remote_serv,
+    VALUE local_host, VALUE local_serv, int type,
+    VALUE resolv_timeout, VALUE connect_timeout, VALUE open_timeout,
+    VALUE _fast_fallback, VALUE _test_mode_settings
+) {
+    if (!NIL_P(open_timeout) && (!NIL_P(resolv_timeout) || !NIL_P(connect_timeout))) {
+        rb_raise(rb_eArgError, "Cannot specify open_timeout along with connect_timeout or resolv_timeout");
+    }
+
     struct inetsock_arg arg;
     arg.self = self;
     arg.io = Qnil;
@@ -189,6 +226,7 @@ rsock_init_inetsock(VALUE self, VALUE remote_host, VALUE remote_serv, VALUE loca
     arg.type = type;
     arg.resolv_timeout = resolv_timeout;
     arg.connect_timeout = connect_timeout;
+    arg.open_timeout = open_timeout;
     return rb_ensure(init_inetsock_internal, (VALUE)&arg,
                      inetsock_cleanup, (VALUE)&arg);
 }
@@ -224,6 +262,7 @@ struct fast_fallback_inetsock_arg
     int type;
     VALUE resolv_timeout;
     VALUE connect_timeout;
+    VALUE open_timeout;
 
     const char *hostp, *portp;
     int *families;
@@ -383,12 +422,22 @@ select_expires_at(
     struct timeval *resolution_delay,
     struct timeval *connection_attempt_delay,
     struct timeval *user_specified_resolv_timeout_at,
-    struct timeval *user_specified_connect_timeout_at
+    struct timeval *user_specified_connect_timeout_at,
+    struct timeval *user_specified_open_timeout_at
 ) {
     if (any_addrinfos(resolution_store)) {
-        return resolution_delay ? resolution_delay : connection_attempt_delay;
+        struct timeval *delay;
+        delay = resolution_delay ? resolution_delay : connection_attempt_delay;
+
+        if (user_specified_open_timeout_at &&
+            timercmp(user_specified_open_timeout_at, delay, <)) {
+            return user_specified_open_timeout_at;
+        }
+        return delay;
     }
 
+    if (user_specified_open_timeout_at) return user_specified_open_timeout_at;
+
     struct timeval *timeout = NULL;
 
     if (user_specified_resolv_timeout_at) {
@@ -506,6 +555,7 @@ init_fast_fallback_inetsock_internal(VALUE v)
     VALUE io = arg->io;
     VALUE resolv_timeout = arg->resolv_timeout;
     VALUE connect_timeout = arg->connect_timeout;
+    VALUE open_timeout = arg->open_timeout;
     VALUE test_mode_settings = arg->test_mode_settings;
     struct addrinfo *remote_ai = NULL, *local_ai = NULL;
     int connected_fd = -1, status = 0, local_status = 0;
@@ -552,8 +602,16 @@ init_fast_fallback_inetsock_internal(VALUE v)
     struct timeval *user_specified_resolv_timeout_at = NULL;
     struct timeval user_specified_connect_timeout_storage;
     struct timeval *user_specified_connect_timeout_at = NULL;
+    struct timeval user_specified_open_timeout_storage;
+    struct timeval *user_specified_open_timeout_at = NULL;
     struct timespec now = current_clocktime_ts();
 
+    if (!NIL_P(open_timeout)) {
+        struct timeval open_timeout_tv = rb_time_interval(open_timeout);
+        user_specified_open_timeout_storage = add_ts_to_tv(open_timeout_tv, now);
+        user_specified_open_timeout_at = &user_specified_open_timeout_storage;
+    }
+
     /* start of hostname resolution */
     if (arg->family_size == 1) {
         arg->wait = -1;
@@ -854,7 +912,8 @@ init_fast_fallback_inetsock_internal(VALUE v)
             resolution_delay_expires_at,
             connection_attempt_delay_expires_at,
             user_specified_resolv_timeout_at,
-            user_specified_connect_timeout_at
+            user_specified_connect_timeout_at,
+            user_specified_open_timeout_at
         );
         if (ends_at) {
             delay = tv_to_timeout(ends_at, now);
@@ -1107,6 +1166,8 @@ init_fast_fallback_inetsock_internal(VALUE v)
             }
         }
 
+        if (is_timeout_tv(user_specified_open_timeout_at, now)) rsock_raise_user_specified_timeout();
+
         if (!any_addrinfos(&resolution_store)) {
             if (!in_progress_fds(arg->connection_attempt_fds_size) &&
                 resolution_store.is_all_finished) {
@@ -1128,9 +1189,7 @@ init_fast_fallback_inetsock_internal(VALUE v)
                 resolution_store.is_all_finished) &&
                 (is_timeout_tv(user_specified_connect_timeout_at, now) ||
                 !in_progress_fds(arg->connection_attempt_fds_size))) {
-                VALUE errno_module = rb_const_get(rb_cObject, rb_intern("Errno"));
-                VALUE etimedout_error = rb_const_get(errno_module, rb_intern("ETIMEDOUT"));
-                rb_raise(etimedout_error, "user specified timeout");
+                rsock_raise_user_specified_timeout();
             }
         }
     }
@@ -1220,8 +1279,16 @@ fast_fallback_inetsock_cleanup(VALUE v)
 }
 
 VALUE
-rsock_init_inetsock(VALUE self, VALUE remote_host, VALUE remote_serv, VALUE local_host, VALUE local_serv, int type, VALUE resolv_timeout, VALUE connect_timeout, VALUE fast_fallback, VALUE test_mode_settings)
-{
+rsock_init_inetsock(
+    VALUE self, VALUE remote_host, VALUE remote_serv,
+    VALUE local_host, VALUE local_serv, int type,
+    VALUE resolv_timeout, VALUE connect_timeout, VALUE open_timeout,
+    VALUE fast_fallback, VALUE test_mode_settings
+) {
+    if (!NIL_P(open_timeout) && (!NIL_P(resolv_timeout) || !NIL_P(connect_timeout))) {
+        rb_raise(rb_eArgError, "Cannot specify open_timeout along with connect_timeout or resolv_timeout");
+    }
+
     if (type == INET_CLIENT && FAST_FALLBACK_INIT_INETSOCK_IMPL == 1 && RTEST(fast_fallback)) {
         struct rb_addrinfo *local_res = NULL;
         char *hostp, *portp;
@@ -1278,6 +1345,7 @@ rsock_init_inetsock(VALUE self, VALUE remote_host, VALUE remote_serv, VALUE loca
             fast_fallback_arg.type = type;
             fast_fallback_arg.resolv_timeout = resolv_timeout;
             fast_fallback_arg.connect_timeout = connect_timeout;
+            fast_fallback_arg.open_timeout = open_timeout;
             fast_fallback_arg.hostp = hostp;
             fast_fallback_arg.portp = portp;
             fast_fallback_arg.additional_flags = additional_flags;
@@ -1314,6 +1382,7 @@ rsock_init_inetsock(VALUE self, VALUE remote_host, VALUE remote_serv, VALUE loca
     arg.type = type;
     arg.resolv_timeout = resolv_timeout;
     arg.connect_timeout = connect_timeout;
+    arg.open_timeout = open_timeout;
 
     return rb_ensure(init_inetsock_internal, (VALUE)&arg,
                      inetsock_cleanup, (VALUE)&arg);
diff --git a/ext/socket/lib/socket.rb b/ext/socket/lib/socket.rb
index da168c9a2964b1..1e30861efaeb3f 100644
--- a/ext/socket/lib/socket.rb
+++ b/ext/socket/lib/socket.rb
@@ -643,7 +643,7 @@ def accept_nonblock(exception: true)
   #
   # [:resolv_timeout] Specifies the timeout in seconds from when the hostname resolution starts.
   # [:connect_timeout] This method sequentially attempts connecting to all candidate destination addresses.<br>The +connect_timeout+ specifies the timeout in seconds from the start of the connection attempt to the last candidate.<br>By default, all connection attempts continue until the timeout occurs.<br>When +fast_fallback:false+ is explicitly specified,<br>a timeout is set for each connection attempt and any connection attempt that exceeds its timeout will be canceled.
-  # [:open_timeout] Specifies the timeout in seconds from the start of the method execution.<br>If this timeout is reached while there are still addresses that have not yet been attempted for connection, no further attempts will be made.
+  # [:open_timeout] Specifies the timeout in seconds from the start of the method execution.<br>If this timeout is reached while there are still addresses that have not yet been attempted for connection, no further attempts will be made.<br>If this option is specified together with other timeout options, an +ArgumentError+ will be raised.
   # [:fast_fallback] Enables the Happy Eyeballs Version 2 algorithm (enabled by default).
   #
   # If a block is given, the block is called with the socket.
diff --git a/ext/socket/raddrinfo.c b/ext/socket/raddrinfo.c
index 6511f9b8b9c5be..bc6c303c36b628 100644
--- a/ext/socket/raddrinfo.c
+++ b/ext/socket/raddrinfo.c
@@ -562,11 +562,7 @@ rb_getaddrinfo(const char *hostp, const char *portp, const struct addrinfo *hint
 
     if (need_free) free_getaddrinfo_arg(arg);
 
-    if (timedout) {
-        VALUE errno_module = rb_const_get(rb_cObject, rb_intern("Errno"));
-        VALUE etimedout_error = rb_const_get(errno_module, rb_intern("ETIMEDOUT"));
-        rb_raise(etimedout_error, "user specified timeout");
-    }
+    if (timedout) rsock_raise_user_specified_timeout();
 
     // If the current thread is interrupted by asynchronous exception, the following raises the exception.
     // But if the current thread is interrupted by timer thread, the following returns; we need to manually retry.
diff --git a/ext/socket/rubysocket.h b/ext/socket/rubysocket.h
index e2daa1b3265bd3..29b8afc1634b80 100644
--- a/ext/socket/rubysocket.h
+++ b/ext/socket/rubysocket.h
@@ -355,7 +355,7 @@ int rsock_socket(int domain, int type, int proto);
 int rsock_detect_cloexec(int fd);
 VALUE rsock_init_sock(VALUE sock, int fd);
 VALUE rsock_sock_s_socketpair(int argc, VALUE *argv, VALUE klass);
-VALUE rsock_init_inetsock(VALUE sock, VALUE remote_host, VALUE remote_serv, VALUE local_host, VALUE local_serv, int type, VALUE resolv_timeout, VALUE connect_timeout, VALUE fast_fallback, VALUE test_mode_settings);
+VALUE rsock_init_inetsock(VALUE sock, VALUE remote_host, VALUE remote_serv, VALUE local_host, VALUE local_serv, int type, VALUE resolv_timeout, VALUE connect_timeout, VALUE open_timeout, VALUE fast_fallback, VALUE test_mode_settings);
 VALUE rsock_init_unixsock(VALUE sock, VALUE path, int server);
 
 struct rsock_send_arg {
@@ -454,6 +454,7 @@ void free_fast_fallback_getaddrinfo_shared(struct fast_fallback_getaddrinfo_shar
 #endif
 
 unsigned int rsock_value_timeout_to_msec(VALUE);
+NORETURN(void rsock_raise_user_specified_timeout(void));
 
 void rsock_init_basicsocket(void);
 void rsock_init_ipsocket(void);
diff --git a/ext/socket/sockssocket.c b/ext/socket/sockssocket.c
index f033f39b2e8888..30860ea257dd16 100644
--- a/ext/socket/sockssocket.c
+++ b/ext/socket/sockssocket.c
@@ -35,7 +35,7 @@ socks_init(VALUE sock, VALUE host, VALUE port)
         init = 1;
     }
 
-    return rsock_init_inetsock(sock, host, port, Qnil, Qnil, INET_SOCKS, Qnil, Qnil, Qfalse, Qnil);
+    return rsock_init_inetsock(sock, host, port, Qnil, Qnil, INET_SOCKS, Qnil, Qnil, Qnil, Qfalse, Qnil);
 }
 
 #ifdef SOCKS5
diff --git a/ext/socket/tcpserver.c b/ext/socket/tcpserver.c
index 8206fe46a9dee9..0069f3c703d47f 100644
--- a/ext/socket/tcpserver.c
+++ b/ext/socket/tcpserver.c
@@ -36,7 +36,7 @@ tcp_svr_init(int argc, VALUE *argv, VALUE sock)
     VALUE hostname, port;
 
     rb_scan_args(argc, argv, "011", &hostname, &port);
-    return rsock_init_inetsock(sock, hostname, port, Qnil, Qnil, INET_SERVER, Qnil, Qnil, Qfalse, Qnil);
+    return rsock_init_inetsock(sock, hostname, port, Qnil, Qnil, INET_SERVER, Qnil, Qnil, Qnil, Qfalse, Qnil);
 }
 
 /*
diff --git a/ext/socket/tcpsocket.c b/ext/socket/tcpsocket.c
index 0467bcfd89630b..22c9f28ab71703 100644
--- a/ext/socket/tcpsocket.c
+++ b/ext/socket/tcpsocket.c
@@ -35,6 +35,7 @@
  *
  * [:resolv_timeout] Specifies the timeout in seconds from when the hostname resolution starts.
  * [:connect_timeout] This method sequentially attempts connecting to all candidate destination addresses.<br>The +connect_timeout+ specifies the timeout in seconds from the start of the connection attempt to the last candidate.<br>By default, all connection attempts continue until the timeout occurs.<br>When +fast_fallback:false+ is explicitly specified,<br>a timeout is set for each connection attempt and any connection attempt that exceeds its timeout will be canceled.
+ * [:open_timeout] Specifies the timeout in seconds from the start of the method execution.<br>If this timeout is reached while there are still addresses that have not yet been attempted for connection, no further attempts will be made.<br>If this option is specified together with other timeout options, an +ArgumentError+ will be raised.
  * [:fast_fallback] Enables the Happy Eyeballs Version 2 algorithm (enabled by default).
  */
 static VALUE
@@ -43,29 +44,32 @@ tcp_init(int argc, VALUE *argv, VALUE sock)
     VALUE remote_host, remote_serv;
     VALUE local_host, local_serv;
     VALUE opt;
-    static ID keyword_ids[4];
-    VALUE kwargs[4];
+    static ID keyword_ids[5];
+    VALUE kwargs[5];
     VALUE resolv_timeout = Qnil;
     VALUE connect_timeout = Qnil;
+    VALUE open_timeout = Qnil;
     VALUE fast_fallback = Qnil;
     VALUE test_mode_settings = Qnil;
 
     if (!keyword_ids[0]) {
         CONST_ID(keyword_ids[0], "resolv_timeout");
         CONST_ID(keyword_ids[1], "connect_timeout");
-        CONST_ID(keyword_ids[2], "fast_fallback");
-        CONST_ID(keyword_ids[3], "test_mode_settings");
+        CONST_ID(keyword_ids[2], "open_timeout");
+        CONST_ID(keyword_ids[3], "fast_fallback");
+        CONST_ID(keyword_ids[4], "test_mode_settings");
     }
 
     rb_scan_args(argc, argv, "22:", &remote_host, &remote_serv,
                         &local_host, &local_serv, &opt);
 
     if (!NIL_P(opt)) {
-        rb_get_kwargs(opt, keyword_ids, 0, 4, kwargs);
+        rb_get_kwargs(opt, keyword_ids, 0, 5, kwargs);
         if (kwargs[0] != Qundef) { resolv_timeout = kwargs[0]; }
         if (kwargs[1] != Qundef) { connect_timeout = kwargs[1]; }
-        if (kwargs[2] != Qundef) { fast_fallback = kwargs[2]; }
-        if (kwargs[3] != Qundef) { test_mode_settings = kwargs[3]; }
+        if (kwargs[2] != Qundef) { open_timeout = kwargs[2]; }
+        if (kwargs[3] != Qundef) { fast_fallback = kwargs[3]; }
+        if (kwargs[4] != Qundef) { test_mode_settings = kwargs[4]; }
     }
 
     if (fast_fallback == Qnil) {
@@ -75,8 +79,8 @@ tcp_init(int argc, VALUE *argv, VALUE sock)
 
     return rsock_init_inetsock(sock, remote_host, remote_serv,
                                local_host, local_serv, INET_CLIENT,
-                               resolv_timeout, connect_timeout, fast_fallback,
-                               test_mode_settings);
+                               resolv_timeout, connect_timeout, open_timeout,
+                               fast_fallback, test_mode_settings);
 }
 
 static VALUE
diff --git a/test/socket/test_tcp.rb b/test/socket/test_tcp.rb
index be6d59b31e7b0b..58fe44a279bcb4 100644
--- a/test/socket/test_tcp.rb
+++ b/test/socket/test_tcp.rb
@@ -73,6 +73,30 @@ def test_initialize_resolv_timeout
     end
   end
 
+  def test_tcp_initialize_open_timeout
+    return if RUBY_PLATFORM =~ /mswin|mingw|cygwin/
+
+    server = TCPServer.new("127.0.0.1", 0)
+    port = server.connect_address.ip_port
+    server.close
+
+    assert_raise(Errno::ETIMEDOUT) do
+      TCPSocket.new(
+        "localhost",
+        port,
+        open_timeout: 0.01,
+        fast_fallback: true,
+        test_mode_settings: { delay: { ipv4: 1000 } }
+      )
+    end
+  end
+
+  def test_initialize_open_timeout_with_other_timeouts
+    assert_raise(ArgumentError) do
+      TCPSocket.new("localhost", 12345, open_timeout: 0.01, resolv_timeout: 0.01)
+    end
+  end
+
   def test_initialize_connect_timeout
     assert_raise(IO::TimeoutError, Errno::ENETUNREACH, Errno::EACCES) do
       TCPSocket.new("192.0.2.1", 80, connect_timeout: 0)
diff --git a/tool/mk_builtin_loader.rb b/tool/mk_builtin_loader.rb
index 6e1f5c666a9bab..a63e1827d5e1db 100644
--- a/tool/mk_builtin_loader.rb
+++ b/tool/mk_builtin_loader.rb
@@ -282,16 +282,21 @@ def generate_cexpr(ofile, lineno, line_file, body_lineno, text, locals, func_nam
 
   # Avoid generating fetches of lvars we don't need. This is imperfect as it
   # will match text inside strings or other false positives.
-  local_candidates = text.scan(/[a-zA-Z_][a-zA-Z0-9_]*/)
+  local_ptrs = []
+  local_candidates = text.gsub(/\bLOCAL_PTR\(\K[a-zA-Z_][a-zA-Z0-9_]*(?=\))/) {
+    local_ptrs << $&; ''
+  }.scan(/[a-zA-Z_][a-zA-Z0-9_]*/)
 
   f.puts '{'
   lineno += 1
   # locals is nil outside methods
   locals&.reverse_each&.with_index{|param, i|
     next unless Symbol === param
-    next unless local_candidates.include?(param.to_s)
+    param = param.to_s
+    lvar = local_candidates.include?(param)
+    next unless lvar or local_ptrs.include?(param)
     f.puts "VALUE *const #{param}__ptr = (VALUE *)&ec->cfp->ep[#{-3 - i}];"
-    f.puts "MAYBE_UNUSED(const VALUE) #{param} = *#{param}__ptr;"
+    f.puts "MAYBE_UNUSED(const VALUE) #{param} = *#{param}__ptr;" if lvar
     lineno += 1
   }
   f.puts "#line #{body_lineno} \"#{line_file}\""