diff --git a/README.md b/README.md
index aa74269..65c388a 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 liferay-javamelody
 =========================
 
-Plugin for JavaMelody to monitor performance in a [Liferay](http://www.liferay.com/) server 7.0 or later.
+Plugin for JavaMelody to monitor performance in a [Liferay](http://www.liferay.com/) server 6.1 or later.
 
 See https://github.com/javamelody/javamelody/wiki
 
diff --git a/pom.xml b/pom.xml
index eed7634..a7b33ed 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
 
 	<groupId>net.bull.javamelody</groupId>
 	<artifactId>liferay-javamelody-hook</artifactId>
-	<version>1.64.0</version>
+	<version>1.63.1</version>
 	<packaging>war</packaging>
 
 	<name>Liferay JavaMelody Plugin</name>
@@ -61,8 +61,8 @@
 				<artifactId>maven-compiler-plugin</artifactId>
 				<version>3.1</version>
 				<configuration>
-					<source>1.8</source>
-					<target>1.8</target>
+					<source>1.6</source>
+					<target>1.6</target>
 				</configuration>
 			</plugin>
 			<plugin>
@@ -137,15 +137,16 @@
 			<scope>provided</scope>
 		</dependency>
 		<dependency>
-		    <groupId>com.liferay.portal</groupId>
-		    <artifactId>com.liferay.portal.kernel</artifactId>
-		    <version>2.21.0</version>
+			<groupId>com.liferay.portal</groupId>
+			<artifactId>portal-service</artifactId>
+			<version>6.1.0</version>
 			<scope>provided</scope>
 		</dependency>
 		<dependency>
-		  	<groupId>org.quartz-scheduler</groupId>
-		  	<artifactId>quartz</artifactId>
-			<version>2.2.3</version>
+			<groupId>com.liferay.portal</groupId>
+			<artifactId>com.liferay.portal.kernel</artifactId>
+			<version>2.21.0</version>
+			<scope>provided</scope>
 		</dependency>
 	</dependencies>
 </project>
diff --git a/src/main/java/net/bull/javamelody/LiferayMonitoringFilter.java b/src/main/java/net/bull/javamelody/LiferayMonitoringFilter.java
index c470417..9e02d87 100644
--- a/src/main/java/net/bull/javamelody/LiferayMonitoringFilter.java
+++ b/src/main/java/net/bull/javamelody/LiferayMonitoringFilter.java
@@ -40,6 +40,8 @@
  * @author Emeric Vernat
  */
 public class LiferayMonitoringFilter extends PluginMonitoringFilter {
+	private boolean liferay7;
+
 	/** {@inheritDoc} */
 	@Override
 	public String getApplicationType() {
@@ -106,8 +108,23 @@ public void doFilter(ServletRequest request, ServletResponse response, FilterCha
 	}
 
 	private boolean isAdmin(HttpServletRequest httpRequest) throws PortalException, SystemException {
-		final long userId = PortalUtil.getUserId(httpRequest);
-		final long companyId = PortalUtil.getDefaultCompanyId();
-		return UserLocalServiceUtil.hasRoleUser(companyId, RoleConstants.ADMINISTRATOR, userId, true);
+		try {
+			if (!liferay7) {
+				// for liferay 6
+				final long userId = com.liferay.portal.util.PortalUtil.getUserId(httpRequest);
+				final long companyId = com.liferay.portal.util.PortalUtil.getDefaultCompanyId();
+				return com.liferay.portal.service.UserLocalServiceUtil.hasRoleUser(companyId,
+						com.liferay.portal.model.RoleConstants.ADMINISTRATOR, userId, true);
+			}
+		} catch (final NoClassDefFoundError e) {
+			liferay7 = true;
+		}
+		if (liferay7) {
+			// for liferay 7
+			final long userId = PortalUtil.getUserId(httpRequest);
+			final long companyId = PortalUtil.getDefaultCompanyId();
+			return UserLocalServiceUtil.hasRoleUser(companyId, RoleConstants.ADMINISTRATOR, userId, true);
+		}
+		return false;
 	}
 }
diff --git a/src/main/webapp/WEB-INF/liferay-plugin-package.properties b/src/main/webapp/WEB-INF/liferay-plugin-package.properties
index 9e1edbc..0864a17 100644
--- a/src/main/webapp/WEB-INF/liferay-plugin-package.properties
+++ b/src/main/webapp/WEB-INF/liferay-plugin-package.properties
@@ -8,7 +8,7 @@ page-url=https://github.com/javamelody/javamelody/wiki
 author=Emeric Vernat
 licenses=ASL
 # compatibility "6.1+" is currently like "6.1.1+,6.1.20+,6.2.0+" (6.1 CE GA2+,6.1 EE GA2+, and 6.2 CE GA1+)
-liferay-versions=7.0.0+
+liferay-versions=6.1+,7.0.0+
 
 # security-manager required by the App Manager of Liferay Marketplace
 #security-manager-enabled=true