diff --git a/setup.py b/setup.py
index eb3c2660..0534aa7c 100644
--- a/setup.py
+++ b/setup.py
@@ -36,6 +36,7 @@
     "google-cloud-core >= 1.4.0, <3.0.0dev",
     "proto-plus >= 1.22.0, <2.0.0dev",
     "proto-plus >= 1.22.2, <2.0.0dev; python_version>='3.11'",
+    "proto-plus >= 1.25.0, <2.0.0dev; python_version>='3.13'",
     "protobuf>=3.20.2,<6.0.0dev,!=3.20.0,!=3.20.1,!=4.21.0,!=4.21.1,!=4.21.2,!=4.21.3,!=4.21.4,!=4.21.5",
 ]
 extras = {"libcst": "libcst >= 0.2.5"}