diff --git a/cmake/modules/Findcetl.cmake b/cmake/modules/Findcetl.cmake
index 58d5dc943..6f611006d 100644
--- a/cmake/modules/Findcetl.cmake
+++ b/cmake/modules/Findcetl.cmake
@@ -6,7 +6,7 @@
 
 include(FetchContent)
 set(cetl_GIT_REPOSITORY "https://github.com/OpenCyphal/cetl.git")
-set(cetl_GIT_TAG "main")
+set(cetl_GIT_TAG "sshirokov/benchmark")
 
 FetchContent_Declare(
     cetl
diff --git a/include/libcyphal/presentation/server.hpp b/include/libcyphal/presentation/server.hpp
index f1f7900d5..91d41a62f 100644
--- a/include/libcyphal/presentation/server.hpp
+++ b/include/libcyphal/presentation/server.hpp
@@ -41,10 +41,10 @@ namespace detail
 
 /// @brief Defines internal base class for any concrete (final) RPC server.
 ///
-class ServerBase : ServerImpl::Callback
+class ServerBase : private ServerImpl::Callback
 {
 public:
-    /// @brief Defines failure type for a base server operations.
+    /// @brief Defines a failure type for a base server operations.
     ///
     /// The set of possible failures of the base server includes transport layer failures.
     /// A strong-typed server extends this type with its own error types (serialization-related).