diff --git a/testable-agent/src/main/java/com/alibaba/testable/agent/PreMain.java b/testable-agent/src/main/java/com/alibaba/testable/agent/PreMain.java
index 58ddd15..e1bdbe7 100755
--- a/testable-agent/src/main/java/com/alibaba/testable/agent/PreMain.java
+++ b/testable-agent/src/main/java/com/alibaba/testable/agent/PreMain.java
@@ -14,6 +14,7 @@ public class PreMain {
     private static final String AND = "&";
     private static final String LOG_LEVEL = "logLevel";
     private static final String DUMP_PATH = "dumpPath";
+    private static final String PKG_PREFIX = "pkgPrefix";
     private static final String EQUAL = "=";
 
     public static void premain(String agentArgs, Instrumentation inst) {
@@ -34,6 +35,8 @@ public class PreMain {
                     GlobalConfig.setLogLevel(v);
                 } else if (k.equals(DUMP_PATH)) {
                     GlobalConfig.setDumpPath(v);
+                } else if (k.equals(PKG_PREFIX)) {
+                    GlobalConfig.setPkgPrefix(v);
                 }
             } else {
                 GlobalConfig.setLogLevel(a);
diff --git a/testable-agent/src/main/java/com/alibaba/testable/agent/transformer/TestableClassTransformer.java b/testable-agent/src/main/java/com/alibaba/testable/agent/transformer/TestableClassTransformer.java
index e36ab19..8042d65 100644
--- a/testable-agent/src/main/java/com/alibaba/testable/agent/transformer/TestableClassTransformer.java
+++ b/testable-agent/src/main/java/com/alibaba/testable/agent/transformer/TestableClassTransformer.java
@@ -36,6 +36,7 @@ import static com.alibaba.testable.agent.util.ClassUtil.toDotSeparateFullClassNa
 public class TestableClassTransformer implements ClassFileTransformer {
 
     private static final String FIELD_DIAGNOSE = "diagnose";
+    private static final String COMMA = ",";
 
     /**
      * Just avoid spend time to scan those surely non-user classes
@@ -105,14 +106,25 @@ public class TestableClassTransformer implements ClassFileTransformer {
         if (null == className) {
             return true;
         }
-        for (String prefix : WHITELIST_PREFIXES) {
-            if (className.startsWith(prefix)) {
-                return false;
+        String whitePrefix = GlobalConfig.getPkgPrefix();
+        if (whitePrefix != null) {
+            for (String prefix : whitePrefix.split(COMMA)) {
+                if (className.startsWith(prefix)) {
+                    // Only consider package in provided list as non-system class
+                    return false;
+                }
             }
-        }
-        for (String prefix : BLACKLIST_PREFIXES) {
-            if (className.startsWith(prefix)) {
-                return true;
+            return true;
+        } else {
+            for (String prefix : WHITELIST_PREFIXES) {
+                if (className.startsWith(prefix)) {
+                    return false;
+                }
+            }
+            for (String prefix : BLACKLIST_PREFIXES) {
+                if (className.startsWith(prefix)) {
+                    return true;
+                }
             }
         }
         return false;
diff --git a/testable-agent/src/main/java/com/alibaba/testable/agent/util/GlobalConfig.java b/testable-agent/src/main/java/com/alibaba/testable/agent/util/GlobalConfig.java
index 178941a..3bb6ef6 100644
--- a/testable-agent/src/main/java/com/alibaba/testable/agent/util/GlobalConfig.java
+++ b/testable-agent/src/main/java/com/alibaba/testable/agent/util/GlobalConfig.java
@@ -12,6 +12,7 @@ public class GlobalConfig {
     private static final String VERBOSE = "verbose";
 
     private static String dumpPath = null;
+    private static String pkgPrefix = null;
 
     public static boolean setLogLevel(String level) {
         if (level.equals(MUTE)) {
@@ -35,4 +36,11 @@ public class GlobalConfig {
         return dumpPath;
     }
 
+    public static String getPkgPrefix() {
+        return pkgPrefix;
+    }
+
+    public static void setPkgPrefix(String pkgPrefix) {
+        GlobalConfig.pkgPrefix = pkgPrefix;
+    }
 }
diff --git a/testable-maven-plugin/src/main/java/com/alibaba/testable/TestableMojo.java b/testable-maven-plugin/src/main/java/com/alibaba/testable/TestableMojo.java
index 9e6b4da..d3e4c33 100644
--- a/testable-maven-plugin/src/main/java/com/alibaba/testable/TestableMojo.java
+++ b/testable-maven-plugin/src/main/java/com/alibaba/testable/TestableMojo.java
@@ -1,5 +1,6 @@
 package com.alibaba.testable;
 
+import com.google.common.base.Strings;
 import org.apache.maven.artifact.Artifact;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
@@ -45,6 +46,12 @@ public class TestableMojo extends AbstractMojo
     @Parameter
     private String dumpPath;
 
+    /**
+     * Package prefixes of class need to be mocked (comma split)
+     */
+    @Parameter
+    private String pkgPrefix;
+
     /**
      * Name of the Testable Agent artifact.
      */
@@ -71,13 +78,17 @@ public class TestableMojo extends AbstractMojo
             getLog().error("failed to fetch project properties");
             return;
         }
+
         String extraArgs = "";
-        if (logLevel != null && !logLevel.isEmpty()) {
+        if (!Strings.isNullOrEmpty(logLevel)) {
             extraArgs += "&logLevel=" + logLevel;
         }
-        if (dumpPath != null && !dumpPath.isEmpty()) {
+        if (!Strings.isNullOrEmpty(dumpPath)) {
             extraArgs += "&dumpPath=" + dumpPath;
         }
+        if (!Strings.isNullOrEmpty(pkgPrefix)) {
+            extraArgs += "&pkgPrefix=" + pkgPrefix;
+        }
         final String oldArgs = projectProperties.getProperty(testArgsPropertyKey);
         String newArgs = (oldArgs == null) ? getAgentJarArgs().trim() : (oldArgs + getAgentJarArgs());
         if (!extraArgs.isEmpty()) {
@@ -91,6 +102,7 @@ public class TestableMojo extends AbstractMojo
         final Artifact testableAgentArtifact = pluginArtifactMap.get(AGENT_ARTIFACT_NAME);
         if (testableAgentArtifact == null) {
             getLog().error("failed to find testable agent jar");
+            return "";
         }
         return " -javaagent:" + testableAgentArtifact.getFile().getAbsolutePath();
     }