diff --git a/tools/run_tests/port_server.py b/tools/run_tests/port_server.py
index 14e82b601eadbef7062397a2c33c791bff43318c..e2be26d182c0f53e2995c7102799e94e6209cdf1 100755
--- a/tools/run_tests/port_server.py
+++ b/tools/run_tests/port_server.py
@@ -42,7 +42,7 @@ import time
 # increment this number whenever making a change to ensure that
 # the changes are picked up by running CI servers
 # note that all changes must be backwards compatible
-_MY_VERSION = 7
+_MY_VERSION = 8
 
 
 if len(sys.argv) == 2 and sys.argv[1] == 'dump_version':
@@ -70,7 +70,7 @@ in_use = {}
 
 def refill_pool(max_timeout, req):
   """Scan for ports not marked for being in use"""
-  for i in range(1025, 32767):
+  for i in range(1025, 32766):
     if len(pool) > 100: break
     if i in in_use:
       age = time.time() - in_use[i]
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index c1254275e6c2eafe5b0fdb3e7b29db621378abe7..413d4145601de56cf2b4a20d2c88c291b7e14ab5 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -1050,7 +1050,23 @@ runs_per_test = args.runs_per_test
 forever = args.forever
 
 
+def _shut_down_legacy_server(legacy_server_port):
+  try:
+    version = int(urllib2.urlopen(
+        'http://localhost:%d/version_number' % legacy_server_port,
+        timeout=10).read())
+  except:
+    pass
+  else:
+    urllib2.urlopen(
+        'http://localhost:%d/quitquitquit' % legacy_server_port).read()
+
+
 def _start_port_server(port_server_port):
+  # Temporary patch to switch the port_server port
+  # see https://github.com/grpc/grpc/issues/7145
+  _shut_down_legacy_server(32767)
+
   # check if a compatible port server is running
   # if incompatible (version mismatch) ==> start a new one
   # if not running ==> start a new one
@@ -1186,7 +1202,7 @@ def _build_and_run(
   # start antagonists
   antagonists = [subprocess.Popen(['tools/run_tests/antagonist.py'])
                  for _ in range(0, args.antagonists)]
-  port_server_port = 32767
+  port_server_port = 32766
   _start_port_server(port_server_port)
   resultset = None
   num_test_failures = 0