diff --git a/pom.xml b/pom.xml
index 06ea7cd..4bd3138 100644
--- a/pom.xml
+++ b/pom.xml
@@ -2,8 +2,13 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <groupId>org.sonatype.oss</groupId>
+        <artifactId>oss-parent</artifactId>
+        <version>7</version>
+    </parent>
     <groupId>us.codecraft</groupId>
-    <version>0.2.0</version>
+    <version>0.2.1-SNAPSHOT</version>
     <modelVersion>4.0.0</modelVersion>
     <packaging>pom</packaging>
     <artifactId>webmagic</artifactId>
@@ -35,7 +40,6 @@
     <modules>
         <module>webmagic-core</module>
         <module>webmagic-extension/</module>
-        <module>webmagic-samples</module>
     </modules>
 
     <dependencyManagement>
@@ -166,5 +170,35 @@
         </plugins>
     </build>
 
+    <profiles>
+        <profile>
+            <id>release-sign-artifacts</id>
+            <activation>
+                <property>
+                    <name>performRelease</name>
+                    <value>true</value>
+                </property>
+            </activation>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-gpg-plugin</artifactId>
+                        <version>1.1</version>
+                        <executions>
+                            <execution>
+                                <id>sign-artifacts</id>
+                                <phase>verify</phase>
+                                <goals>
+                                    <goal>sign</goal>
+                                </goals>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
 
 </project>
diff --git a/webmagic-core/pom.xml b/webmagic-core/pom.xml
index cf42d2a..90e36bb 100644
--- a/webmagic-core/pom.xml
+++ b/webmagic-core/pom.xml
@@ -5,7 +5,7 @@
     <parent>
         <groupId>us.codecraft</groupId>
         <artifactId>webmagic</artifactId>
-        <version>0.2.0</version>
+        <version>0.2.1-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
 
diff --git a/webmagic-extension/pom.xml b/webmagic-extension/pom.xml
index 7ef5aca..ae9bc5d 100644
--- a/webmagic-extension/pom.xml
+++ b/webmagic-extension/pom.xml
@@ -5,7 +5,7 @@
     <parent>
         <groupId>us.codecraft</groupId>
         <artifactId>webmagic</artifactId>
-        <version>0.2.0</version>
+        <version>0.2.1-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>