Index: lldb/include/lldb/Host/posix/ConnectionFileDescriptorPosix.h
===================================================================
--- lldb/include/lldb/Host/posix/ConnectionFileDescriptorPosix.h
+++ lldb/include/lldb/Host/posix/ConnectionFileDescriptorPosix.h
@@ -16,6 +16,7 @@
 #include "lldb/lldb-forward.h"
 
 #include "lldb/Host/Pipe.h"
+#include "lldb/Host/Terminal.h"
 #include "lldb/Utility/Connection.h"
 #include "lldb/Utility/IOObject.h"
 #include "lldb/Utility/Predicate.h"
@@ -110,6 +111,7 @@
   // BytesAvailable to disconnect, we won't try to read again.
   bool m_waiting_for_accept = false;
   bool m_child_processes_inherit;
+  TerminalState m_saved_term_state;
 
   std::string m_uri;
 
Index: lldb/source/Host/posix/ConnectionFileDescriptorPosix.cpp
===================================================================
--- lldb/source/Host/posix/ConnectionFileDescriptorPosix.cpp
+++ lldb/source/Host/posix/ConnectionFileDescriptorPosix.cpp
@@ -247,7 +247,9 @@
         return eConnectionStatusError;
       }
 
-      if (::isatty(fd)) {
+      Terminal term{fd};
+      if (term.IsATerminal()) {
+        m_saved_term_state.Save(term, false);
         // Set up serial terminal emulation
         struct termios options;
         ::tcgetattr(fd, &options);
@@ -341,6 +343,9 @@
   // Prevents reads and writes during shutdown.
   m_shutting_down = true;
 
+  m_saved_term_state.Restore();
+  m_saved_term_state.Clear();
+
   Status error = m_read_sp->Close();
   Status error2 = m_write_sp->Close();
   if (error.Fail() || error2.Fail())
Index: lldb/test/API/functionalities/gdb_remote_client/TestPty.py
===================================================================
--- lldb/test/API/functionalities/gdb_remote_client/TestPty.py
+++ lldb/test/API/functionalities/gdb_remote_client/TestPty.py
@@ -9,6 +9,16 @@
     mydir = TestBase.compute_mydir(__file__)
     server_socket_class = PtyServerSocket
 
+    def setUp(self):
+        super().setUp()
+        import termios
+        self.orig_attr = termios.tcgetattr(self.server._socket._slave)
+
+    def assert_attr_restored(self):
+        import termios
+        self.assertEqual(termios.tcgetattr(self.server._socket._slave),
+                         self.orig_attr)
+
     def test_process_connect_sync(self):
         """Test the process connect command in synchronous mode"""
         try:
@@ -19,6 +29,7 @@
                         substrs=['Process', 'stopped'])
         finally:
             self.dbg.GetSelectedTarget().GetProcess().Kill()
+        self.assert_attr_restored()
 
     def test_process_connect_async(self):
         """Test the process connect command in asynchronous mode"""
@@ -35,3 +46,4 @@
             self.dbg.GetSelectedTarget().GetProcess().Kill()
         lldbutil.expect_state_changes(self, self.dbg.GetListener(),
                                       self.process(), [lldb.eStateExited])
+        self.assert_attr_restored()