diff --git a/src/test/java/net/kemitix/mon/TypeAliasTest.java b/src/test/java/net/kemitix/mon/TypeAliasTest.java
index a077205..08a5448 100644
--- a/src/test/java/net/kemitix/mon/TypeAliasTest.java
+++ b/src/test/java/net/kemitix/mon/TypeAliasTest.java
@@ -68,6 +68,15 @@ public class TypeAliasTest {
         assertThat(anAlias1).isEqualTo(anAlias2);
     }
 
+    @Test
+    public void shouldNotBeEqualWhenValuesAreNotTheSame() {
+        //given
+        final AnAlias valueA = AnAlias.of("value a");
+        final AnAlias valueB = AnAlias.of("value b");
+        //then
+        assertThat(valueA).isNotEqualTo(valueB);
+    }
+
     @Test
     public void shouldBeEqualToRawValue() {
         //given