diff --git a/honoka/src/honoka_imengine.cpp b/honoka/src/honoka_imengine.cpp
index c381652..b825d1b 100644
--- a/honoka/src/honoka_imengine.cpp
+++ b/honoka/src/honoka_imengine.cpp
@@ -340,6 +340,7 @@
  */
 void HonokaInstance::changeConvertor(const String &name)
 {
+    if (m_conversion) return;
     for(unsigned int i = 0;i < convertors.size();i ++) {
         if (convertors[i]->getPropertyName() == name) {
             m_convertor = convertors[i];