diff --git a/aos/logging/implementations.cc b/aos/logging/implementations.cc
index cfc14c0..04831a2 100644
--- a/aos/logging/implementations.cc
+++ b/aos/logging/implementations.cc
@@ -131,10 +131,6 @@
 void SetImplementation(LogImplementation *implementation, bool update_global) {
   internal::Context *context = internal::Context::Get();
 
-  if (implementation == nullptr) {
-    AOS_LOG(FATAL, "SetImplementation got invalid implementation");
-  }
-
   context->implementation = implementation;
   if (update_global) {
     SetGlobalImplementation(implementation);
@@ -150,6 +146,10 @@
   return old;
 }
 
+LogImplementation *GetImplementation() {
+  return internal::Context::Get()->implementation;
+}
+
 void Init() {
   static absl::once_flag once;
   absl::call_once(once, DoInit);
@@ -264,7 +264,7 @@
 
 void RegisterCallbackImplementation(
     const ::std::function<void(const LogMessage &)> &callback,
-    bool update_global = true) {
+    bool update_global) {
   Init();
   SetImplementation(new CallbackLogImplementation(callback), update_global);
 }