Index: lldb/tools/lldb-server/lldb-platform.cpp
===================================================================
--- lldb/tools/lldb-server/lldb-platform.cpp
+++ lldb/tools/lldb-server/lldb-platform.cpp
@@ -241,11 +241,11 @@
     return -1;
 
   // Make a port map for a port range that was specified.
-  if (min_gdbserver_port < max_gdbserver_port) {
+  if (min_gdbserver_port && min_gdbserver_port < max_gdbserver_port) {
     for (uint16_t port = min_gdbserver_port; port < max_gdbserver_port; ++port)
       gdbserver_portmap[port] = LLDB_INVALID_PROCESS_ID;
-  } else if (min_gdbserver_port != max_gdbserver_port) {
-    fprintf(stderr, "error: --min-gdbserver-port (%u) is greater than "
+  } else if (min_gdbserver_port || max_gdbserver_port) {
+    fprintf(stderr, "error: --min-gdbserver-port (%u) is not lower than "
                     "--max-gdbserver-port (%u)\n",
             min_gdbserver_port, max_gdbserver_port);
     option_error = 3;