diff --git a/lib/perfdata/graphitewriter.cpp b/lib/perfdata/graphitewriter.cpp
index a01f6c48b..1b6461d51 100644
--- a/lib/perfdata/graphitewriter.cpp
+++ b/lib/perfdata/graphitewriter.cpp
@@ -299,7 +299,7 @@ void GraphiteWriter::SendMetric(const String& prefix, const String& name, double
 	msgbuf << "\n";
 	String metric = msgbuf.str();
 
-	ObjectLock olock(this);
+	boost::mutex::scoped_lock lock(m_StreamMutex);
 
 	if (!GetConnected())
 		return;
diff --git a/lib/perfdata/graphitewriter.hpp b/lib/perfdata/graphitewriter.hpp
index 6934d13b3..ec4c5bbfe 100644
--- a/lib/perfdata/graphitewriter.hpp
+++ b/lib/perfdata/graphitewriter.hpp
@@ -27,6 +27,7 @@
 #include "base/timer.hpp"
 #include "base/workqueue.hpp"
 #include <fstream>
+#include <boost/thread/mutex.hpp>
 
 namespace icinga
 {
@@ -54,6 +55,7 @@ protected:
 
 private:
 	Stream::Ptr m_Stream;
+	boost::mutex m_StreamMutex;
 	WorkQueue m_WorkQueue{10000000, 1};
 
 	Timer::Ptr m_ReconnectTimer;