diff --git a/honoka/src/honoka_imengine.cpp b/honoka/src/honoka_imengine.cpp
index 1fe9a11..a253258 100644
--- a/honoka/src/honoka_imengine.cpp
+++ b/honoka/src/honoka_imengine.cpp
@@ -202,18 +202,24 @@
                 void* plugin = dlopen(d.c_str(), RTLD_LAZY);
                 if (!plugin) continue;
                 createInstanceFunc *getInstance = (createInstanceFunc *)dlsym(plugin,"getHonokaPluginInstance");
-                if (!getInstance) {
+                deleteInstanceFunc *deleteInstance = (deleteInstanceFunc *)dlsym(plugin,"deleteHonokaPluginInstance");
+                getPluginVersionFunc *getPluginVersion = (getPluginVersionFunc *)dlsym(plugin,"getHonokaPluginVersion");
+                if ((!getInstance) || (!deleteInstance) || (!getPluginVersion)) {
                     dlclose(plugin);
                     continue;
                 }
-                HonokaPluginBase *p = getInstance(_scim_config);
-                if (p->getPluginType() == "Convertor") {
-                    convertors.push_back(static_cast<Convertor *>(p));
-                } else
-                if (p->getPluginType() == "PreEditor") {
-                    preeditors.push_back(static_cast<PreEditor *>(p));
+                if (getPluginVersion() == HONOKA_PLUGIN_VERSION) {
+                    HonokaPluginBase *p = getInstance(_scim_config);
+                    if (p->getPluginType() == "Convertor") {
+                        convertors.push_back(static_cast<Convertor *>(p));
+                    } else
+                    if (p->getPluginType() == "PreEditor") {
+                        preeditors.push_back(static_cast<PreEditor *>(p));
+                    } else {
+                        deleteInstance(p);
+                        dlclose(plugin);
+                    }
                 } else {
-                    delete p;
                     dlclose(plugin);
                 }
             }
diff --git a/honoka/src/honoka_imengine.h b/honoka/src/honoka_imengine.h
index 4370d9f..1200397 100644
--- a/honoka/src/honoka_imengine.h
+++ b/honoka/src/honoka_imengine.h
@@ -36,6 +36,8 @@
 #include <scim_iconv.h>
 
 typedef HonokaPluginBase* createInstanceFunc(ConfigPointer);
+typedef void deleteInstanceFunc(HonokaPluginBase *);
+typedef int getPluginVersionFunc();
 
 using namespace scim;
 using namespace std;
diff --git a/honoka/src/honokapluginbase.h b/honoka/src/honokapluginbase.h
index dccd9aa..169f0ad 100644
--- a/honoka/src/honokapluginbase.h
+++ b/honoka/src/honokapluginbase.h
@@ -27,6 +27,8 @@
 #include <scim.h>
 #define Uses_SCIM_CONFIG_BASE
 
+#define HONOKA_PLUGIN_VERSION 1
+
 using namespace std;
 using namespace scim;
 
@@ -34,14 +36,19 @@
 @author TAM (Teppei Tamra)
 */
 
-#define HonokaPluginRegister(pName) extern "C" {HonokaPluginBase *getHonokaPluginInstance(ConfigPointer cfg){return new pName(cfg);}}
+#define HonokaPluginRegister(pName) \
+    extern "C" { \
+        HonokaPluginBase *getHonokaPluginInstance(ConfigPointer cfg) { return new pName(cfg); } \
+        void deleteHonokaPluginInstance(HonokaPluginBase *o) { delete static_cast<pName *>(o); } \
+        int getHonokaPluginVersion() { return(HONOKA_PLUGIN_VERSION); } \
+    }
 
 class HonokaPluginBase{
 protected:
     HonokaPluginBase(const String pluginType);
+    ~HonokaPluginBase();
 
 public:
-    ~HonokaPluginBase();
     
     String getPluginType();