diff --git a/subprojects/kotlinx-serialization/src/commonSample/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerCommonSample.kt b/subprojects/kotlinx-serialization/src/commonSample/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerCommonSample.kt
index 3a24bca65..a3151137a 100644
--- a/subprojects/kotlinx-serialization/src/commonSample/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerCommonSample.kt
+++ b/subprojects/kotlinx-serialization/src/commonSample/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerCommonSample.kt
@@ -36,7 +36,8 @@ internal class ZeroAsByteSerializerCommonSample {
         val serializer = ZeroAsByteSerializer()
         val other = ZeroAsByteSerializer()
         val equality: Boolean = serializer == other
-        assertTrue(equality)
+        val message = "Instances of '$serializer' should be equal."
+        assertTrue(equality, message)
     }
 
     @Test
diff --git a/subprojects/kotlinx-serialization/src/commonTest/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerTest.kt b/subprojects/kotlinx-serialization/src/commonTest/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerTest.kt
index bca63c267..db263da34 100644
--- a/subprojects/kotlinx-serialization/src/commonTest/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerTest.kt
+++ b/subprojects/kotlinx-serialization/src/commonTest/kotlin/org/kotools/types/kotlinx/serialization/ZeroAsByteSerializerTest.kt
@@ -18,7 +18,8 @@ class ZeroAsByteSerializerTest {
         val serializer = ZeroAsByteSerializer()
         val other: Any = "Oops"
         val actual: Boolean = serializer == other
-        assertFalse(actual)
+        val message = "Instance of '$serializer' shouldn't equal another type."
+        assertFalse(actual, message)
     }
 
     // ----------------------- Serialization operations ------------------------