diff --git a/tools/interop_matrix/client_matrix.py b/tools/interop_matrix/client_matrix.py
index d52f5fc8fae..83b6be709fe 100644
--- a/tools/interop_matrix/client_matrix.py
+++ b/tools/interop_matrix/client_matrix.py
@@ -269,6 +269,7 @@ LANG_RELEASE_MATRIX = {
             ('v1.39.0', ReleaseInfo()),
             ('v1.40.1', ReleaseInfo()),
             ('v1.41.0', ReleaseInfo()),
+            ('v1.42.0', ReleaseInfo()),
         ]),
     'python':
         OrderedDict(