diff --git a/honoka/plugins/primeprediction.cpp b/honoka/plugins/primeprediction.cpp
index 6fcdc42..8d19659 100644
--- a/honoka/plugins/primeprediction.cpp
+++ b/honoka/plugins/primeprediction.cpp
@@ -39,6 +39,7 @@
 
 #include <sys/types.h>
 #include <sys/wait.h>
+#include <sys/shm.h>
 
 
 // �ץ饤�����󲽤Τ��ޤ��ʤ��Ǥ���
@@ -48,7 +49,13 @@
 PrimePrediction::PrimePrediction(ConfigPointer cfg) : Predictor(cfg)
 {
     m_iconv.set_encoding ("EUC-JP");
-    con = false;
+    mid = shmget(IPC_PRIVATE,sizeof(bool),IPC_CREAT | 0666);
+    if (mid != -1) {
+        con = (bool *)shmat(mid,0,0);
+        con[0] = false;
+        // shmat���Ի��Υ��顼�����ϡ���
+        // Ʊ��ץ����dzμ¤�Ʊ��ID�ʤ鼺�Ԥ��褦���ʤ����⤹�뤬��
+    }
     lookup_method = cfg->read(HONOKA_CONFIG_PRIME_PREDICTION_LM,String(HONOKA_DEFAULT_PRIME_PREDICTION_LM));
     if ((lookup_method != "lookup") &&
         (lookup_method != "lookup_all") &&
@@ -67,6 +74,7 @@
 PrimePrediction::~PrimePrediction()
 {
     disconnect();
+    if (mid != -1) shmctl(mid,IPC_RMID,0);
 }
 
 
@@ -105,7 +113,8 @@
 ResultList PrimePrediction::getPredictionList(const WideString &str)
 {
     ResultList l;
-    if (!con) return l;
+    if (mid == -1) return l;
+    if (!con[0]) return l;
     String s = lookup_method + "\t";
     String t;
     m_iconv.convert(t,str);
@@ -142,12 +151,13 @@
  */
 void PrimePrediction::disconnect()
 {
-    if (!con) return;
+    if (mid == -1) return;
+    if (con[0]) return;
     String s = "close\n";
     write(ifd,s.c_str(),s.length());
     close(ifd);
     close(ofd);
-    con = false;
+    con[0] = false;
 }
 
 
@@ -156,17 +166,18 @@
  */
 bool PrimePrediction::connect()
 {
+    if (mid == -1) return false;
     int in_fd[2],out_fd[2],i;
-    if (con) return true;
+    if (con[0]) return true;
     if (pipe(in_fd) == -1) return false;
     if (pipe(out_fd) == -1) return false;
-    switch(vfork()) {
+    switch(fork()) {
         case -1: {
             close(in_fd[0]);
             close(in_fd[1]);
             close(out_fd[0]);
             close(out_fd[1]);
-            con = false;
+            con[0] = false;
             return false;
         }
         case 0: {
@@ -176,9 +187,9 @@
             dup2(out_fd[1],1);
             close(in_fd[0]);
             close(out_fd[1]);
-            con = true;
+            con[0] = true;
             execlp("prime",NULL);
-            con = false;
+            con[0] = false;
             _exit(0);
         }
     }
@@ -195,7 +206,8 @@
  */
 bool PrimePrediction::isConnected()
 {
-    return con;
+    if (mid == -1) return false;
+    return con[0];
 }
 
 
diff --git a/honoka/plugins/primeprediction.h b/honoka/plugins/primeprediction.h
index a5ce978..a8e1a4f 100644
--- a/honoka/plugins/primeprediction.h
+++ b/honoka/plugins/primeprediction.h
@@ -36,6 +36,8 @@
 #include <scim.h>
 #include <scim_iconv.h>
 #include <scim_attribute.h>
+#include <sys/types.h>
+#include <sys/ipc.h>
 
 /**
 @author TAM (Teppei Tamra)
@@ -59,8 +61,9 @@
     String lookup_method;
     int ifd;
     int ofd;
-    bool con;
+    bool *con;
     IConvert m_iconv;
+    int mid;
 protected:
     ResultEntry parser(const String &str);
 };