diff --git a/Foundation/include/Poco/Mutex_WIN32.h b/Foundation/include/Poco/Mutex_WIN32.h
index ee6e3dc0a..6ae48d005 100644
--- a/Foundation/include/Poco/Mutex_WIN32.h
+++ b/Foundation/include/Poco/Mutex_WIN32.h
@@ -42,6 +42,10 @@ private:
 	CRITICAL_SECTION _cs;
 	int _lockCount;
 	const bool _recursive;
+
+private:
+	MutexImpl(const MutexImpl&);
+	MutexImpl& operator = (const MutexImpl&);
 };
 
 
diff --git a/Foundation/include/Poco/Mutex_WINCE.h b/Foundation/include/Poco/Mutex_WINCE.h
index ba9123f17..8f672d46d 100644
--- a/Foundation/include/Poco/Mutex_WINCE.h
+++ b/Foundation/include/Poco/Mutex_WINCE.h
@@ -42,6 +42,10 @@ private:
 	HANDLE _mutex;
 	int _lockCount;
 	const bool _recursive;
+
+private:
+	MutexImpl(const MutexImpl&);
+	MutexImpl& operator = (const MutexImpl&);
 };