diff --git a/cpp/include/Ice/MetricsObserverI.h b/cpp/include/Ice/MetricsObserverI.h
index d102f16fd41..113f781d562 100644
--- a/cpp/include/Ice/MetricsObserverI.h
+++ b/cpp/include/Ice/MetricsObserverI.h
@@ -652,7 +652,7 @@ class ObserverFactoryT : public Updater, private IceUtil::Mutex
     IceInternal::MetricsAdminIPtr _metrics;
     const std::string _name;
     MetricsMapSeqType _maps;
-    std::atomic<int> _enabled;
+    std::atomic<bool> _enabled;
     UpdaterPtr _updater;
 };
 
diff --git a/cpp/include/IceUtil/Shared.h b/cpp/include/IceUtil/Shared.h
index 8cefadd9bf3..74a1928fbc7 100644
--- a/cpp/include/IceUtil/Shared.h
+++ b/cpp/include/IceUtil/Shared.h
@@ -6,6 +6,7 @@
 #define ICE_UTIL_SHARED_H
 
 #include <IceUtil/Config.h>
+#include <atomic>
 
 //
 // Base classes for reference counted types. The IceUtil::Handle
diff --git a/cpp/src/Ice/Instance.cpp b/cpp/src/Ice/Instance.cpp
index 07249842397..a82c71b184c 100644
--- a/cpp/src/Ice/Instance.cpp
+++ b/cpp/src/Ice/Instance.cpp
@@ -212,7 +212,7 @@ class Timer : public IceUtil::Timer
     virtual void runTimerTask(const IceUtil::TimerTaskPtr&);
 
     IceUtil::Mutex _mutex;
-    std::atomic<int> _hasObserver;
+    std::atomic<bool> _hasObserver;
     ObserverHelperT<Ice::Instrumentation::ThreadObserver> _observer;
 };