diff --git a/src/test/java/com/github/f4b6a3/ulid/TestSuite.java b/src/test/java/com/github/f4b6a3/ulid/TestSuite.java
index b6de9b8..b76e08a 100644
--- a/src/test/java/com/github/f4b6a3/ulid/TestSuite.java
+++ b/src/test/java/com/github/f4b6a3/ulid/TestSuite.java
@@ -3,13 +3,10 @@ package com.github.f4b6a3.ulid;
 import org.junit.runner.RunWith;
 import org.junit.runners.Suite;
 
-import com.github.f4b6a3.ulid.factory.DefaultFactoryTest;
-import com.github.f4b6a3.ulid.factory.MonotonicFactoryTest;
-
 @RunWith(Suite.class)
 @Suite.SuiteClasses({
-	MonotonicFactoryTest.class,
-	DefaultFactoryTest.class,
+	UlidFactoryMonotonicTest.class,
+	UlidFactoryDefaultfTest.class,
 	UlidTest.class,
 })
 
diff --git a/src/test/java/com/github/f4b6a3/ulid/factory/DefaultFactoryTest.java b/src/test/java/com/github/f4b6a3/ulid/UlidFactoryDefaultfTest.java
similarity index 60%
rename from src/test/java/com/github/f4b6a3/ulid/factory/DefaultFactoryTest.java
rename to src/test/java/com/github/f4b6a3/ulid/UlidFactoryDefaultfTest.java
index 05b42af..eca2121 100644
--- a/src/test/java/com/github/f4b6a3/ulid/factory/DefaultFactoryTest.java
+++ b/src/test/java/com/github/f4b6a3/ulid/UlidFactoryDefaultfTest.java
@@ -1,4 +1,4 @@
-package com.github.f4b6a3.ulid.factory;
+package com.github.f4b6a3.ulid;
 
 import org.junit.Test;
 
@@ -8,10 +8,9 @@ import com.github.f4b6a3.ulid.UlidFactory;
 
 import static org.junit.Assert.*;
 
-import java.util.HashSet;
 import java.util.Random;
 
-public class DefaultFactoryTest extends UlidFactoryTest {
+public class UlidFactoryDefaultfTest extends UlidFactoryTest {
 
 	@Test
 	public void testGetUlid() {
@@ -30,35 +29,6 @@ public class DefaultFactoryTest extends UlidFactoryTest {
 		checkCreationTime(list, startTime, endTime);
 	}
 
-	private void checkNullOrInvalid(Ulid[] list) {
-		for (Ulid ulid : list) {
-			assertNotNull("ULID is null", ulid);
-		}
-	}
-
-	private void checkUniqueness(Ulid[] list) {
-
-		HashSet<Ulid> set = new HashSet<>();
-
-		for (Ulid ulid : list) {
-			assertTrue(String.format("ULID is duplicated %s", ulid), set.add(ulid));
-		}
-
-		assertEquals("There are duplicated ULIDs", set.size(), list.length);
-	}
-
-	private void checkCreationTime(Ulid[] list, long startTime, long endTime) {
-
-		assertTrue("Start time was after end time", startTime <= endTime);
-
-		for (Ulid ulid : list) {
-			long creationTime = ulid.getTime();
-			assertTrue("Creation time was before start time " + creationTime + " " + startTime,
-					creationTime >= startTime);
-			assertTrue("Creation time was after end time", creationTime <= endTime);
-		}
-	}
-
 	@Test
 	public void testGetUlidInParallel() throws InterruptedException {
 
diff --git a/src/test/java/com/github/f4b6a3/ulid/factory/MonotonicFactoryTest.java b/src/test/java/com/github/f4b6a3/ulid/UlidFactoryMonotonicTest.java
similarity index 65%
rename from src/test/java/com/github/f4b6a3/ulid/factory/MonotonicFactoryTest.java
rename to src/test/java/com/github/f4b6a3/ulid/UlidFactoryMonotonicTest.java
index 6634282..662787d 100644
--- a/src/test/java/com/github/f4b6a3/ulid/factory/MonotonicFactoryTest.java
+++ b/src/test/java/com/github/f4b6a3/ulid/UlidFactoryMonotonicTest.java
@@ -1,4 +1,4 @@
-package com.github.f4b6a3.ulid.factory;
+package com.github.f4b6a3.ulid;
 
 import org.junit.Test;
 
@@ -9,10 +9,9 @@ import com.github.f4b6a3.ulid.UlidFactory;
 import static org.junit.Assert.*;
 
 import java.util.Arrays;
-import java.util.HashSet;
 import java.util.Random;
 
-public class MonotonicFactoryTest extends UlidFactoryTest {
+public class UlidFactoryMonotonicTest extends UlidFactoryTest {
 
 	@Test
 	public void testGetUlid() {
@@ -32,35 +31,6 @@ public class MonotonicFactoryTest extends UlidFactoryTest {
 		checkCreationTime(list, startTime, endTime);
 	}
 
-	private void checkNullOrInvalid(Ulid[] list) {
-		for (Ulid ulid : list) {
-			assertNotNull("ULID is null", ulid);
-		}
-	}
-
-	private void checkUniqueness(Ulid[] list) {
-
-		HashSet<Ulid> set = new HashSet<>();
-
-		for (Ulid ulid : list) {
-			assertTrue(String.format("ULID is duplicated %s", ulid), set.add(ulid));
-		}
-
-		assertEquals("There are duplicated ULIDs", set.size(), list.length);
-	}
-
-	private void checkCreationTime(Ulid[] list, long startTime, long endTime) {
-
-		assertTrue("Start time was after end time", startTime <= endTime);
-
-		for (Ulid ulid : list) {
-			long creationTime = ulid.getTime();
-			assertTrue("Creation time was before start time " + creationTime + " " + startTime,
-					creationTime >= startTime);
-			assertTrue("Creation time was after end time", creationTime <= endTime);
-		}
-	}
-
 	private void checkOrdering(Ulid[] list) {
 		Ulid[] other = Arrays.copyOf(list, list.length);
 		Arrays.sort(other);
diff --git a/src/test/java/com/github/f4b6a3/ulid/factory/UlidFactoryTest.java b/src/test/java/com/github/f4b6a3/ulid/UlidFactoryTest.java
similarity index 56%
rename from src/test/java/com/github/f4b6a3/ulid/factory/UlidFactoryTest.java
rename to src/test/java/com/github/f4b6a3/ulid/UlidFactoryTest.java
index 7af1fc7..e36863b 100644
--- a/src/test/java/com/github/f4b6a3/ulid/factory/UlidFactoryTest.java
+++ b/src/test/java/com/github/f4b6a3/ulid/UlidFactoryTest.java
@@ -1,4 +1,8 @@
-package com.github.f4b6a3.ulid.factory;
+package com.github.f4b6a3.ulid;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
 
 import java.util.HashSet;
 import java.util.Random;
@@ -27,6 +31,35 @@ public abstract class UlidFactoryTest {
 		return processors;
 	}
 
+	protected void checkNullOrInvalid(Ulid[] list) {
+		for (Ulid ulid : list) {
+			assertNotNull("ULID is null", ulid);
+		}
+	}
+
+	protected void checkUniqueness(Ulid[] list) {
+
+		HashSet<Ulid> set = new HashSet<>();
+
+		for (Ulid ulid : list) {
+			assertTrue(String.format("ULID is duplicated %s", ulid), set.add(ulid));
+		}
+
+		assertEquals("There are duplicated ULIDs", set.size(), list.length);
+	}
+	
+	protected void checkCreationTime(Ulid[] list, long startTime, long endTime) {
+
+		assertTrue("Start time was after end time", startTime <= endTime);
+
+		for (Ulid ulid : list) {
+			long creationTime = ulid.getTime();
+			assertTrue("Creation time was before start time " + creationTime + " " + startTime,
+					creationTime >= startTime);
+			assertTrue("Creation time was after end time", creationTime <= endTime);
+		}
+	}
+
 	protected static class TestThread extends Thread {
 
 		public static Set<UUID> hashSet = new HashSet<>();
diff --git a/src/test/java/com/github/f4b6a3/ulid/demo/DemoTest.java b/src/test/java/com/github/f4b6a3/ulid/demo/DemoTest.java
index 79d6104..9e22bf9 100644
--- a/src/test/java/com/github/f4b6a3/ulid/demo/DemoTest.java
+++ b/src/test/java/com/github/f4b6a3/ulid/demo/DemoTest.java
@@ -16,7 +16,7 @@ public class DemoTest {
 		for (int i = 0; i < max; i++) {
 			System.out.println(UlidCreator.getUlid());
 		}
-		
+
 		System.out.println(HORIZONTAL_LINE);
 		System.out.println("### Monotonic ULID");
 		System.out.println(HORIZONTAL_LINE);