diff --git a/bin/interpreter.cmd b/bin/interpreter.cmd
index 4a501f09ab..fd6af3df22 100644
--- a/bin/interpreter.cmd
+++ b/bin/interpreter.cmd
@@ -46,6 +46,14 @@ if exist "%ZEPPELIN_HOME%\zeppelin-interpreter\target\classes" (
     set ZEPPELIN_CLASSPATH=%ZEPPELIN_CLASSPATH%;"!ZEPPELIN_INTERPRETER_JAR!"
 )
 
+REM add test classes for unittest
+if exist "%ZEPPELIN_HOME%\zeppelin-interpreter\target\test-classes" (
+    set ZEPPELIN_CLASSPATH=%ZEPPELIN_CLASSPATH%;"%ZEPPELIN_HOME%\zeppelin-interpreter\target\test-classes"
+)
+if exist "%ZEPPELIN_HOME%\zeppelin-zengine\target\test-classes" (
+    set ZEPPELIN_CLASSPATH=%ZEPPELIN_CLASSPATH%;"%ZEPPELIN_HOME%\zeppelin-zengine\target\test-classes"
+)
+
 call "%bin%\functions.cmd" ADDJARINDIR "%ZEPPELIN_HOME%\zeppelin-interpreter\target\lib"
 call "%bin%\functions.cmd" ADDJARINDIR "%INTERPRETER_DIR%"
 
diff --git a/bin/interpreter.sh b/bin/interpreter.sh
index 38d0f69e70..a81c8f2106 100755
--- a/bin/interpreter.sh
+++ b/bin/interpreter.sh
@@ -63,6 +63,15 @@ else
   ZEPPELIN_INTP_CLASSPATH+=":${ZEPPELIN_INTERPRETER_JAR}"
 fi
 
+# add test classes for unittest
+if [[ -d "${ZEPPELIN_HOME}/zeppelin-interpreter/target/test-classes" ]]; then
+  ZEPPELIN_INTP_CLASSPATH+=":${ZEPPELIN_HOME}/zeppelin-interpreter/target/test-classes"
+fi
+if [[ -d "${ZEPPELIN_HOME}/zeppelin-zengine/target/test-classes" ]]; then
+  ZEPPELIN_INTP_CLASSPATH+=":${ZEPPELIN_HOME}/zeppelin-zengine/target/test-classes"
+fi
+
+
 addJarInDirForIntp "${ZEPPELIN_HOME}/zeppelin-interpreter/target/lib"
 addJarInDirForIntp "${INTERPRETER_DIR}"