diff --git a/src/ecs/component.rs b/src/ecs/component.rs
index 5308302..6b05bea 100644
--- a/src/ecs/component.rs
+++ b/src/ecs/component.rs
@@ -135,3 +135,27 @@ impl Flags {
         value | flags.bits()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use super::super::entity::Entity;
+    use super::super::relation::Relation;
+
+    #[test]
+    fn component_from_and_to_entity() {
+        let entity = Entity::new_checked(1337, 42).unwrap();
+        let component: Component = entity.into();
+        assert!(component.is_entity());
+        assert_eq!(entity, component.try_into().unwrap());
+    }
+
+    #[test]
+    fn component_from_and_to_relation() {
+        let relation = Relation::new_checked(20, 21).unwrap();
+        let component: Component = relation.into();
+        assert!(component.is_relation());
+        assert_eq!(relation, component.try_into().unwrap());
+    }
+}