diff --git a/src/common/tvgLock.h b/src/common/tvgLock.h
index d8bf7269..59f68d0d 100644
--- a/src/common/tvgLock.h
+++ b/src/common/tvgLock.h
@@ -28,6 +28,7 @@
 #define _DISABLE_CONSTEXPR_MUTEX_CONSTRUCTOR
 
 #include <mutex>
+#include "tvgTaskScheduler.h"
 
 namespace tvg {
 
@@ -42,13 +43,17 @@ namespace tvg {
 
         ScopedLock(Key& k)
         {
-            k.mtx.lock();
-            key = &k;
+            if (TaskScheduler::threads() > 0) {
+                k.mtx.lock();
+                key = &k;
+            }
         }
 
         ~ScopedLock()
         {
-            key->mtx.unlock();
+            if (TaskScheduler::threads() > 0) {
+                key->mtx.unlock();
+            }
         }
     };
 
diff --git a/src/renderer/tvgRender.cpp b/src/renderer/tvgRender.cpp
index 90432d65..6ecaf77b 100644
--- a/src/renderer/tvgRender.cpp
+++ b/src/renderer/tvgRender.cpp
@@ -32,6 +32,20 @@
 /* External Class Implementation                                        */
 /************************************************************************/
 
+uint32_t RenderMethod::ref()
+{
+    ScopedLock lock(key);
+    return (++refCnt);
+}
+
+
+uint32_t RenderMethod::unref()
+{
+    ScopedLock lock(key);
+    return (--refCnt);
+}
+
+
 void RenderTransform::override(const Matrix& m)
 {
     this->m = m;
diff --git a/src/renderer/tvgRender.h b/src/renderer/tvgRender.h
index 670338dc..8d52df71 100644
--- a/src/renderer/tvgRender.h
+++ b/src/renderer/tvgRender.h
@@ -246,17 +246,8 @@ private:
     Key key;
 
 public:
-    uint32_t ref()
-    {
-        ScopedLock lock(key);
-        return (++refCnt);
-    }
-
-    uint32_t unref()
-    {
-        ScopedLock lock(key);
-        return (--refCnt);
-    }
+    uint32_t ref();
+    uint32_t unref();
 
     virtual ~RenderMethod() {}
     virtual RenderData prepare(const RenderShape& rshape, RenderData data, const RenderTransform* transform, Array<RenderData>& clips, uint8_t opacity, RenderUpdateFlag flags, bool clipper) = 0;