diff --git a/src/main/java/org/codelibs/fess/helper/KeyMatchHelper.java b/src/main/java/org/codelibs/fess/helper/KeyMatchHelper.java
index 306f7077e..368fd480c 100644
--- a/src/main/java/org/codelibs/fess/helper/KeyMatchHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/KeyMatchHelper.java
@@ -23,6 +23,7 @@ import java.util.Map;
 
 import javax.annotation.PostConstruct;
 
+import org.codelibs.core.lang.StringUtil;
 import org.codelibs.core.misc.Pair;
 import org.codelibs.fess.Constants;
 import org.codelibs.fess.entity.SearchRequestParams.SearchRequestType;
@@ -78,7 +79,10 @@ public class KeyMatchHelper {
                     });
 
                     if (boolQuery.hasClauses()) {
-                        final String virtualHost = keyMatch.getVirtualHost();
+                        String virtualHost = keyMatch.getVirtualHost();
+                        if (StringUtil.isBlank(virtualHost)) {
+                            virtualHost = StringUtil.EMPTY;
+                        }
                         Map<String, Pair<QueryBuilder, ScoreFunctionBuilder<?>>> queryMap = keyMatchQueryMap.get(virtualHost);
                         if (queryMap == null) {
                             queryMap = new HashMap<>();
diff --git a/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java b/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java
index 05d327fcc..6df7cd01e 100644
--- a/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/SearchLogHelper.java
@@ -121,7 +121,7 @@ public class SearchLogHelper {
             searchLog.setLanguages(StringUtil.EMPTY);
         }
         final String virtualHostKey = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
-        if (virtualHostKey != null) {
+        if (StringUtil.isNotBlank(virtualHostKey)) {
             searchLog.setVirtualHost(virtualHostKey);
         } else {
             searchLog.setVirtualHost(StringUtil.EMPTY);
diff --git a/src/main/java/org/codelibs/fess/helper/SystemHelper.java b/src/main/java/org/codelibs/fess/helper/SystemHelper.java
index 7986b3910..24310b179 100644
--- a/src/main/java/org/codelibs/fess/helper/SystemHelper.java
+++ b/src/main/java/org/codelibs/fess/helper/SystemHelper.java
@@ -358,6 +358,7 @@ public class SystemHelper {
         ComponentUtil.getLdapManager().updateConfig();
         ComponentUtil.getRelatedContentHelper().update();
         ComponentUtil.getRelatedQueryHelper().update();
+        ComponentUtil.getKeyMatchHelper().update();
     }
 
     public String updateConfiguration() {