diff --git a/app/node/node.cpp b/app/node/node.cpp
index 186c03532..aae84fed2 100644
--- a/app/node/node.cpp
+++ b/app/node/node.cpp
@@ -175,7 +175,13 @@ void Node::ClearCachedValuesInParameters(const rational &start_range, const rati
 
 QVariant Node::Run(NodeOutput* output, const rational& time)
 {
-  return Value(output, time);
+  run_lock_.lock();
+
+  QVariant v = Value(output, time);
+
+  run_lock_.unlock();
+
+  return v;
 }
 
 NodeParam *Node::ParamAt(int index)
diff --git a/app/node/node.h b/app/node/node.h
index eff4c4fe8..571339afb 100644
--- a/app/node/node.h
+++ b/app/node/node.h
@@ -281,10 +281,15 @@ private:
   NodeOutput* last_processed_parameter_;
 
   /**
-   * @brief Used for thread safety
+   * @brief Used for thread safety from main thread
    */
   QMutex lock_;
 
+  /**
+   * @brief Used for thread safety between multiple threads
+   */
+  QMutex run_lock_;
+
 private slots:
   void InputChanged(rational start, rational end);