diff --git a/scim-wnn/src/scim_wnn_imengine.cpp b/scim-wnn/src/scim_wnn_imengine.cpp
index 742fbc4..90052d5 100644
--- a/scim-wnn/src/scim_wnn_imengine.cpp
+++ b/scim-wnn/src/scim_wnn_imengine.cpp
@@ -215,6 +215,7 @@
     yosoku = _scim_config->read(String(SCIM_CONFIG_WNN_YOSOKU),SCIM_DEFAULT_WNN_YOSOKU);
     sType = _scim_config->read(String(SCIM_CONFIG_WNN_SERVERTYPE),String(SCIM_DEFAULT_WNN_SERVERTYPE));
     
+    if (wnn) delete(wnn);
     #ifdef HAVE_LIBANTHY
     if (sType == "Anthy")
         wnn = new AnthyConversion(_scim_config);