diff --git a/code/FBX/FBXExporter.cpp b/code/FBX/FBXExporter.cpp
index 915b4aca7..7419f3d15 100644
--- a/code/FBX/FBXExporter.cpp
+++ b/code/FBX/FBXExporter.cpp
@@ -69,6 +69,8 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <unordered_set>
 #include <iostream>
 
+#include <iostream> //wangyi
+
 // RESOURCES:
 // https://code.blender.org/2013/08/fbx-binary-file-format-specification/
 // https://wiki.blender.org/index.php/User:Mont29/Foundation/FBX_File_Structure