diff --git a/pom.xml b/pom.xml
index ed85d7705..ba0c4d5ae 100644
--- a/pom.xml
+++ b/pom.xml
@@ -37,6 +37,7 @@
 		<!-- Main Framework -->
 		<dbflute.version>1.1.9</dbflute.version>
 		<lastaflute.version>1.1.1</lastaflute.version>
+		<lasta.di.version>0.8.0-B-SNAPSHOT</lasta.di.version>
 		<lasta.taglib.version>0.7.3</lasta.taglib.version>
 		<lasta.job.version>0.5.3</lasta.job.version>
 		<mailflute.version>0.6.0</mailflute.version>
@@ -1058,6 +1059,11 @@
 	</repositories>
 	<dependencies>
 		<!-- lastaflute -->
+		<dependency>
+			<groupId>org.lastaflute</groupId>
+			<artifactId>lasta-di</artifactId>
+			<version>${lasta.di.version}</version>
+		</dependency>
 		<dependency>
 			<groupId>org.lastaflute</groupId>
 			<artifactId>lastaflute</artifactId>
diff --git a/src/main/java/org/codelibs/fess/expression/engine/SaiExpressionEngine.java b/src/main/java/org/codelibs/fess/expression/engine/SaiExpressionEngine.java
deleted file mode 100644
index 236a09049..000000000
--- a/src/main/java/org/codelibs/fess/expression/engine/SaiExpressionEngine.java
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- * Copyright 2012-2019 CodeLibs Project and the Others.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
- * either express or implied. See the License for the specific language
- * governing permissions and limitations under the License.
- */
-package org.codelibs.fess.expression.engine;
-
-import java.util.Map;
-
-import javax.script.ScriptEngine;
-import javax.script.ScriptException;
-
-import org.lastaflute.di.core.LaContainer;
-import org.lastaflute.di.core.expression.engine.JavaScriptExpressionEngine;
-
-public class SaiExpressionEngine extends JavaScriptExpressionEngine {
-    @Override
-    protected Object actuallyEvaluate(String exp, Map<String, ? extends Object> contextMap, LaContainer container, String firstName,
-            Object firstComponent) {
-        final ScriptEngine engine = prepareScriptEngineManager().getEngineByName("sai");
-        if (firstName != null) {
-            engine.put(firstName, firstComponent);
-        }
-        try {
-            return engine.eval(exp);
-        } catch (ScriptException | RuntimeException e) {
-            throwJavaScriptExpressionException(exp, contextMap, container, e);
-            return null; // unreachable
-        }
-    }
-}
diff --git a/src/main/resources/lasta_di.properties b/src/main/resources/lasta_di.properties
index c797c5e7b..2eaa13597 100644
--- a/src/main/resources/lasta_di.properties
+++ b/src/main/resources/lasta_di.properties
@@ -9,4 +9,5 @@ smart.deploy.mode.location = fess_env.properties: lasta_di.smart.deploy.mode
 smart.package1 = org.codelibs.fess.app
 
 # script engine
-dixml.script.expression.engine=org.codelibs.fess.expression.engine.SaiExpressionEngine
+dixml.script.managed.engine.name = sai
+