diff --git a/.github/workflows/clang-tidy.yaml b/.github/workflows/clang-tidy.yaml
index 69f16befc5..a16bc8b3b8 100644
--- a/.github/workflows/clang-tidy.yaml
+++ b/.github/workflows/clang-tidy.yaml
@@ -17,9 +17,9 @@ jobs:
       matrix:
         include:
           - cmake_options: all-options-abiv1-preview
-            warning_limit: 349
+            warning_limit: 346
           - cmake_options: all-options-abiv2-preview
-            warning_limit: 353
+            warning_limit: 350
     env:
       CC: /usr/bin/clang-22
       CXX: /usr/bin/clang++-22
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0cb9a2a121..c257958b9b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -51,6 +51,9 @@ Increment the:
 * [CODE HEALTH] Move func_http_main classes into anonymous namespace
   [#4128](https://github.com/open-telemetry/opentelemetry-cpp/pull/4128)
 
+* [CODE HEALTH] Move func_grpc_main classes into anonymous namespace
+  [#4129](https://github.com/open-telemetry/opentelemetry-cpp/pull/4129)
+
 ## [1.27.0] 2026-05-13
 
 * [RELEASE] Bump main branch to 1.27.0-dev
diff --git a/functional/otlp/func_grpc_main.cc b/functional/otlp/func_grpc_main.cc
index df871633e0..808bb227bc 100644
--- a/functional/otlp/func_grpc_main.cc
+++ b/functional/otlp/func_grpc_main.cc
@@ -56,6 +56,9 @@ static std::string opt_cert_dir;
 static std::string opt_test_name;
 static TestMode opt_mode = TestMode::kNone;
 
+namespace
+{
+
 /*
   Log parsing
 */
@@ -319,6 +322,8 @@ struct test_case
   test_func_t m_func;
 };
 
+}  // namespace
+
 static int test_basic();
 
 static int test_cert_not_found();