diff --git a/src/test/java/cleanzephyr/rubycollect4j/RubyHashTest.java b/src/test/java/cleanzephyr/rubycollect4j/RubyHashTest.java
index <HASH>..<HASH> 100644
--- a/src/test/java/cleanzephyr/rubycollect4j/RubyHashTest.java
+++ b/src/test/java/cleanzephyr/rubycollect4j/RubyHashTest.java
@@ -11,6 +11,7 @@ import static cleanzephyr.rubycollect4j.RubyHash.newRubyHash;
 import static com.google.common.collect.Maps.newHashMap;
 import static com.google.common.collect.Maps.newLinkedHashMap;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
 
 public class RubyHashTest {
@@ -45,4 +46,16 @@ public class RubyHashTest {
     assertNull(rh.assoc(7));
   }
 
+  @Test(expected = UnsupportedOperationException.class)
+  public void testCompareByIdentity() {
+    rh = newRubyHash();
+    rh.compareByIdentity();
+  }
+
+  @Test
+  public void testCompareByIdentityʔ() {
+    rh = newRubyHash();
+    assertFalse(rh.comparedByIdentityʔ());
+  }
+
 }
Add test for RubyHash::testCompareByIdentityʔ