diff --git a/src/test/java/net/kemitix/mon/IdentityTest.java b/src/test/java/net/kemitix/mon/IdentityTest.java
index c93a2e9..5a1b3f3 100644
--- a/src/test/java/net/kemitix/mon/IdentityTest.java
+++ b/src/test/java/net/kemitix/mon/IdentityTest.java
@@ -17,7 +17,7 @@ public class IdentityTest implements WithAssertions {
         //when
         final Identity<Integer> idInt = idString.map(String::length);
         //then
-        idInt.map(id -> assertThat(id).isEqualTo(3));
+        assertIdentityContains(idInt, 3);
     }
 
     @Test
@@ -31,7 +31,11 @@ public class IdentityTest implements WithAssertions {
                                                                  .map(String::toLowerCase)
                                                                  .map(String::getBytes);
         //then
-        idBytes.map(bytes -> assertThat(bytes).isEqualTo("par".getBytes()));
+        assertIdentityContains(idBytes, "par".getBytes());
+    }
+
+    private <T> void assertIdentityContains(final Identity<T> identity, final T expected) {
+        identity.map(id -> assertThat(id).isEqualTo(expected));
     }
 
 }
diff --git a/src/test/java/net/kemitix/mon/MonTest.java b/src/test/java/net/kemitix/mon/MonTest.java
index 91b51f0..96272c3 100644
--- a/src/test/java/net/kemitix/mon/MonTest.java
+++ b/src/test/java/net/kemitix/mon/MonTest.java
@@ -15,7 +15,7 @@ public class MonTest {
         //when
         final Mon<String> wrap = Mon.of("test");
         //then
-        wrap.map(value -> assertThat(value).isEqualTo("test"));
+        assertMonContains(wrap, "test");
     }
 
     @Test
@@ -25,7 +25,7 @@ public class MonTest {
         //when
         final Mon<String> updated = wrap.map(a -> a + " more");
         //then
-        updated.map(value -> assertThat(value).isEqualTo("test more"));
+        assertMonContains(updated, "test more");
     }
 
     @Test
@@ -35,7 +35,7 @@ public class MonTest {
         //when
         final Mon<Integer> result = wrap.map(String::length);
         //then
-        result.map(value -> assertThat(value).isEqualTo(4));
+        assertMonContains(result, 4);
     }
 
     @Test
@@ -52,7 +52,7 @@ public class MonTest {
         final Optional<Mon<String>> longAndInvalid = factory.apply("value is too long");
         //then
         assertThat(shortAndValid).isNotEmpty();
-        shortAndValid.ifPresent(valid -> valid.map(value -> assertThat(value).contains("value okay")));
+        shortAndValid.ifPresent(valid -> assertMonContains(valid, "value okay"));
         assertThat(longAndInvalid).isEmpty();
     }
 
@@ -76,7 +76,7 @@ public class MonTest {
         final Mon<Mon<String>> nonFlatMapped = wrap.map(Mon::of);
         final Mon<String> result = wrap.flatMap(Mon::of);
         //then
-        result.map(value -> assertThat(value).isEqualTo("test"));
+        assertMonContains(result, "test");
         nonFlatMapped.map(inner -> assertThat(result).isEqualTo(inner));
     }
 
@@ -144,4 +144,8 @@ public class MonTest {
         assertThat(one).isNotEqualTo(notAMon);
         assertThat(one).isNotEqualTo(null);
     }
+
+    private <T> void assertMonContains(final Mon<T> wrap, final T expected) {
+        wrap.map(value -> assertThat(value).isEqualTo(expected));
+    }
 }