diff --git a/packages/google-api-core/pyproject.toml b/packages/google-api-core/pyproject.toml
index 19642422ac21..ef775c6c8cb0 100644
--- a/packages/google-api-core/pyproject.toml
+++ b/packages/google-api-core/pyproject.toml
@@ -44,8 +44,8 @@ classifiers = [
 ]
 dependencies = [
   "googleapis-common-protos >= 1.63.2, < 2.0.0",
-  "protobuf >= 4.25.8, < 8.0.0",
-  "proto-plus >= 1.22.3, < 2.0.0",
+  "protobuf >= 5.29.6, < 8.0.0",
+  "proto-plus >= 1.24.0, < 2.0.0",
   "proto-plus >= 1.25.0, < 2.0.0; python_version >= '3.13'",
   "google-auth >= 2.14.1, < 3.0.0",
   "requests >= 2.25.0, < 3.0.0",
diff --git a/packages/google-api-core/testing/constraints-3.10.txt b/packages/google-api-core/testing/constraints-3.10.txt
index 444eb4f13dcf..ad51ebca8241 100644
--- a/packages/google-api-core/testing/constraints-3.10.txt
+++ b/packages/google-api-core/testing/constraints-3.10.txt
@@ -6,9 +6,9 @@
 # e.g., if pyproject.toml has "foo >= 1.14.0, < 2.0.0dev",
 # Then this file should have foo==1.14.0
 googleapis-common-protos==1.63.2
-protobuf==4.25.8
+protobuf==5.29.6
 google-auth==2.14.1
 requests==2.25.0
 grpcio==1.41.0
 grpcio-status==1.41.0
-proto-plus==1.22.3
+proto-plus==1.24.0
diff --git a/packages/google-api-core/testing/constraints-async-rest-3.10.txt b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
index cfa4ed99ceb9..4f4b34dd3c9b 100644
--- a/packages/google-api-core/testing/constraints-async-rest-3.10.txt
+++ b/packages/google-api-core/testing/constraints-async-rest-3.10.txt
@@ -6,10 +6,10 @@
 # e.g., if pyproject.toml has "foo >= 1.14.0, < 2.0.0dev",
 # Then this file should have foo==1.14.0
 googleapis-common-protos==1.63.2
-protobuf==4.25.8
+protobuf==5.29.6
 google-auth==2.14.1
 requests==2.25.0
 grpcio==1.41.0
 grpcio-status==1.41.0
-proto-plus==1.22.3
+proto-plus==1.24.0
 aiohttp==3.13.4