diff --git a/build.gradle b/build.gradle
index 683e4870..dbb29372 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,6 +1,7 @@
 plugins {
     id 'java'
     id 'application'
+    id 'checkstyle'
 }
 
 group 'seedu.duke'
@@ -10,6 +11,10 @@ repositories {
     mavenCentral()
 }
 
+checkstyle {
+    toolVersion = '8.23'
+}
+
 application {
     // Change this to your main class.
     mainClassName = "duke/Duke"
diff --git a/src/test/java/DukeTest.java b/src/test/java/DukeTest.java
index 99e0e46a..83d4bada 100644
--- a/src/test/java/DukeTest.java
+++ b/src/test/java/DukeTest.java
@@ -1,4 +1,9 @@
+import duke.Duke;
+import duke.command.AddCommand;
+import duke.command.Command;
+import duke.command.ExitCommand;
 import duke.exception.DukeException;
+import duke.parser.Parser;
 import org.junit.jupiter.api.Test;
 
 import static org.junit.jupiter.api.Assertions.*;
@@ -12,7 +17,7 @@ public void dummyTest(){
     @Test
     public void testExitCommand() throws DukeException {
            Duke duke= new Duke("data/tasks.txt");
-            Command c=Parser.parse("bye");
+            Command c= Parser.parse("bye");
          assertTrue(c instanceof ExitCommand);
     }
     @Test