diff --git a/src/test/java/net/kemitix/mon/MaybeTest.java b/src/test/java/net/kemitix/mon/MaybeTest.java
index ecd0190..ba68b3c 100644
--- a/src/test/java/net/kemitix/mon/MaybeTest.java
+++ b/src/test/java/net/kemitix/mon/MaybeTest.java
@@ -32,6 +32,15 @@ public class MaybeTest {
         assertThat(nothing()).isSameAs(nothing());
     }
 
+    @Test
+    public void equality() {
+        assertThat(just(1)).isEqualTo(just(1));
+        assertThat(just(1)).isNotEqualTo(just(2));
+        assertThat(just(1)).isNotEqualTo(nothing());
+        assertThat(nothing()).isEqualTo(nothing());
+        assertThat(just(1).equals("1")).isFalse();
+    }
+
     @Test
     public void maybeAllowsNull() {
         assertThat(just(1)).isEqualTo(maybe(1));