diff --git a/unit/TestAll.java b/unit/TestAll.java
index 9488c6b..d26e0c7 100644
--- a/unit/TestAll.java
+++ b/unit/TestAll.java
@@ -7,6 +7,7 @@ import org.junit.runners.Suite.*;
 @SuiteClasses({
     TestCursor.class,
     TestTextUtils.class,
+    TestAsmUtils.class,
     TestListUtils.class
 })
 public class TestAll {
diff --git a/unit/TestAsmUtils.java b/unit/TestAsmUtils.java
new file mode 100644
index 0000000..4c5adb6
--- /dev/null
+++ b/unit/TestAsmUtils.java
@@ -0,0 +1,37 @@
+import org.junit.*;
+import org.junit.runner.*;
+import static org.junit.Assert.*;
+import static net.loveruby.cflat.utils.AsmUtils.*;
+
+public class TestAsmUtils {
+    static public void main(String[] args) {
+        JUnitCore.main(TestAsmUtils.class.getName());
+    }
+
+    @Test public void test_align() {
+        assertEquals(0, align(0, 4));
+        assertEquals(4, align(1, 4));
+        assertEquals(4, align(2, 4));
+        assertEquals(4, align(3, 4));
+        assertEquals(4, align(4, 4));
+        assertEquals(8, align(5, 4));
+        assertEquals(8, align(6, 4));
+        assertEquals(8, align(7, 4));
+        assertEquals(8, align(8, 4));
+        assertEquals(12, align(9, 4));
+
+        assertEquals(0, align(0, 8));
+        assertEquals(8, align(1, 8));
+        assertEquals(8, align(2, 8));
+        assertEquals(8, align(7, 8));
+        assertEquals(8, align(8, 8));
+        assertEquals(16, align(9, 8));
+        assertEquals(16, align(16, 8));
+        assertEquals(24, align(17, 8));
+
+        assertEquals(0, align(0, 16));
+        assertEquals(16, align(1, 16));
+        assertEquals(16, align(16, 16));
+        assertEquals(32, align(17, 16));
+    }
+}