diff --git a/src/vstdlib/random.cpp b/src/vstdlib/random.cpp
index 4ab584e7..6ced4a21 100644
--- a/src/vstdlib/random.cpp
+++ b/src/vstdlib/random.cpp
@@ -186,7 +186,7 @@ CGaussianRandomStream::CGaussianRandomStream(IUniformRandomStream* pUniformStrea
 //-----------------------------------------------------------------------------
 void CGaussianRandomStream::AttachToStream(IUniformRandomStream* pUniformStream)
 {
-	std::lock_guard<std::mutex> l(m_mutex);
+	AUTO_LOCK( m_mutex );
 
 	m_pUniformStream = pUniformStream;
 	m_bHaveValue = false;
@@ -198,7 +198,7 @@ void CGaussianRandomStream::AttachToStream(IUniformRandomStream* pUniformStream)
 //-----------------------------------------------------------------------------
 float CGaussianRandomStream::RandomFloat(float flMean, float flStdDev)
 {
-	std::lock_guard<std::mutex> l(m_mutex);
+	AUTO_LOCK( m_mutex );
 
 	IUniformRandomStream* pUniformStream = m_pUniformStream ? m_pUniformStream : s_pUniformStream;
 	float fac, rsq, v1, v2;
diff --git a/src/vstdlib/random.h b/src/vstdlib/random.h
index 294ef2aa..dddf6e96 100644
--- a/src/vstdlib/random.h
+++ b/src/vstdlib/random.h
@@ -85,7 +85,7 @@ private:
 	bool	m_bHaveValue;
 	float	m_flRandomValue;
 
-	std::mutex m_mutex;
+	CThreadMutex m_mutex;
 };