diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.h
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.h
@@ -16,6 +16,7 @@
 #include "GDBRemoteCommunicationServerCommon.h"
 #include "lldb/Host/Socket.h"
 
+#include "llvm/ADT/Optional.h"
 #include "llvm/Support/Error.h"
 
 namespace lldb_private {
@@ -86,8 +87,10 @@
 
   void SetInferiorArguments(const lldb_private::Args &args);
 
+  // Set port if you want to use a specific port number.
+  // Otherwise port will be set to the port that was chosen for you.
   Status LaunchGDBServer(const lldb_private::Args &args, std::string hostname,
-                         lldb::pid_t &pid, uint16_t &port,
+                         lldb::pid_t &pid, llvm::Optional<uint16_t> &port,
                          std::string &socket_name);
 
   void SetPendingGdbServer(lldb::pid_t pid, uint16_t port,
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.cpp b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.cpp
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationServerPlatform.cpp
@@ -157,8 +157,8 @@
 
 Status GDBRemoteCommunicationServerPlatform::LaunchGDBServer(
     const lldb_private::Args &args, std::string hostname, lldb::pid_t &pid,
-    uint16_t &port, std::string &socket_name) {
-  if (port == UINT16_MAX) {
+    llvm::Optional<uint16_t> &port, std::string &socket_name) {
+  if (!port) {
     llvm::Expected<uint16_t> available_port = m_port_map.GetNextAvailablePort();
     if (available_port)
       port = *available_port;
@@ -179,7 +179,7 @@
 
   Log *log(GetLogIfAnyCategoriesSet(LIBLLDB_LOG_PLATFORM));
   LLDB_LOGF(log, "Launching debugserver with: %s:%u...", hostname.c_str(),
-            port);
+            *port);
 
   // Do not run in a new session so that it can not linger after the platform
   // closes.
@@ -194,7 +194,7 @@
 #if !defined(__APPLE__)
   url << m_socket_scheme << "://";
 #endif
-  uint16_t *port_ptr = &port;
+  uint16_t *port_ptr = port.getPointer();
   if (m_socket_protocol == Socket::ProtocolTcp) {
     llvm::StringRef platform_scheme;
     llvm::StringRef platform_ip;
@@ -205,7 +205,7 @@
                                platform_port, platform_path);
     UNUSED_IF_ASSERT_DISABLED(ok);
     assert(ok);
-    url << platform_ip.str() << ":" << port;
+    url << platform_ip.str() << ":" << *port;
   } else {
     socket_name = GetDomainSocketPath("gdbserver").GetPath();
     url << socket_name;
@@ -219,11 +219,11 @@
   if (pid != LLDB_INVALID_PROCESS_ID) {
     std::lock_guard<std::recursive_mutex> guard(m_spawned_pids_mutex);
     m_spawned_pids.insert(pid);
-    if (port > 0)
-      m_port_map.AssociatePortWithProcess(port, pid);
+    if (*port > 0)
+      m_port_map.AssociatePortWithProcess(*port, pid);
   } else {
-    if (port > 0)
-      m_port_map.FreePort(port);
+    if (*port > 0)
+      m_port_map.FreePort(*port);
   }
   return error;
 }
@@ -243,12 +243,15 @@
   packet.SetFilePos(::strlen("qLaunchGDBServer;"));
   llvm::StringRef name;
   llvm::StringRef value;
-  uint16_t port = UINT16_MAX;
+  llvm::Optional<uint16_t> port;
   while (packet.GetNameColonValue(name, value)) {
     if (name.equals("host"))
       hostname = std::string(value);
-    else if (name.equals("port"))
-      value.getAsInteger(0, port);
+    else if (name.equals("port")) {
+      // Make the Optional valid so we can use its value
+      port = 0;
+      value.getAsInteger(0, port.getValue());
+    }
   }
 
   lldb::pid_t debugserver_pid = LLDB_INVALID_PROCESS_ID;
@@ -269,8 +272,9 @@
             __FUNCTION__, debugserver_pid);
 
   StreamGDBRemote response;
+  assert(port);
   response.Printf("pid:%" PRIu64 ";port:%u;", debugserver_pid,
-                  port + m_port_offset);
+                  *port + m_port_offset);
   if (!socket_name.empty()) {
     response.PutCString("socket_name:");
     response.PutStringAsRawHex8(socket_name);
diff --git a/lldb/tools/lldb-server/lldb-platform.cpp b/lldb/tools/lldb-server/lldb-platform.cpp
--- a/lldb/tools/lldb-server/lldb-platform.cpp
+++ b/lldb/tools/lldb-server/lldb-platform.cpp
@@ -349,13 +349,13 @@
     if (platform.IsConnected()) {
       if (inferior_arguments.GetArgumentCount() > 0) {
         lldb::pid_t pid = LLDB_INVALID_PROCESS_ID;
-        uint16_t port = 0;
+        llvm::Optional<uint16_t> port = 0;
         std::string socket_name;
         Status error = platform.LaunchGDBServer(inferior_arguments,
                                                 "", // hostname
                                                 pid, port, socket_name);
         if (error.Success())
-          platform.SetPendingGdbServer(pid, port, socket_name);
+          platform.SetPendingGdbServer(pid, *port, socket_name);
         else
           fprintf(stderr, "failed to start gdbserver: %s\n", error.AsCString());
       }