diff --git a/src/main/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2.cljc b/src/main/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2.cljc
index cd86a21..b3554bc 100644
--- a/src/main/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2.cljc
+++ b/src/main/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2.cljc
@@ -14,14 +14,14 @@
 (s/def ::Object
   (s/and
    ::owl/Class
-   (sh/map-spec (s/keys :opt-un [::id ::type ::attachment ::bcc ::bto ::cc ::to]))))
+   (sh/map-spec (s/keys :opt [::id ::type ::attachment ::bcc ::bto ::cc ::to]))))
 
 ;http://www.w3.org/ns/activitystreams#Link
 ;TODO: definition in progress
 (s/def ::Link 
   (s/and
    ::owl/Class
-   (sh/map-spec (s/keys :opt-un [::id ::type]))))
+   (sh/map-spec (s/keys :opt [::id ::type]))))
 
 ;http://www.w3.org/ns/activitystreams#Activity
 ;TODO: Define more properties necessary for Like
@@ -29,7 +29,7 @@
   (s/and
    ::owl/Class
    ::Object
-   (sh/map-spec (s/keys :opt-un [::result ::object ::actor]))))
+   (sh/map-spec (s/keys :opt [::result ::object ::actor]))))
 
 ;http://www.w3.org/ns/activitystreams#Relationship
 ;We only have this class, since the property "object" is in the domain "Activity" and "Relationship"
@@ -38,7 +38,7 @@
   (s/and
    ::owl/Class
    ::Object
-   (sh/map-spec (s/keys :opt-un [::object]))))
+   (sh/map-spec (s/keys :opt [::object]))))
 
 ;http://www.w3.org/ns/activitystreams#Like
 (s/def ::Like
diff --git a/src/test/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2_test.cljc b/src/test/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2_test.cljc
index e0b6745..aca1290 100644
--- a/src/test/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2_test.cljc
+++ b/src/test/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2_test.cljc
@@ -25,36 +25,36 @@
 
 (deftest object-test
   (is (s/valid? ::sut/object "http://example.org/posts/1"))
-  (is (s/valid? ::sut/object {:type "Note",
-                              :content "A simple note"}))
+  (is (s/valid? ::sut/object {::sut/type "Note",
+                              ::sut/content "A simple note"}))
   (is (s/valid? ::sut/object ["http://example.org/posts/1",
-                              {:type "Note",
-                               :summary "A simple note",
-                               :content "That is a tree."}])))
+                              {::sut/type "Note",
+                               ::sut/summary "A simple note",
+                               ::sut/content "That is a tree."}])))
 
 (deftest result-test
   (is (s/valid? ::sut/result "https://social.bla/alyssa/result/RANDOMHASH"))
-  (is (s/valid? ::sut/result {:type "http://www.types.example/flightstatus", :name "On Time"}))
-  (is (s/valid? ::sut/result {:type "Link" :href "http://www.target.de"}))
+  (is (s/valid? ::sut/result {::sut/type "http://www.types.example/flightstatus", ::sut/name "On Time"}))
+  (is (s/valid? ::sut/result {::sut/type "Link" ::sut/href "http://www.target.de"}))
   (is (not (s/valid? ::sut/result nil)))
   (is (not (s/valid? ::sut/result 47))))
 
 
 (deftest attachment-test
   (is (s/valid? ::sut/attachment
-                [{:type "Image",
-                  :content "This is what he looks like.",
-                  :url "http://example.org/cat.jpeg"}])))
+                [{::sut/type "Image",
+                  ::sut/content "This is what he looks like.",
+                  ::sut/url "http://example.org/cat.jpeg"}])))
 
 (deftest actor-test
   (is (s/valid? ::sut/actor "http://sally.example.org"))
-  (is (s/valid? ::sut/actor {:type "Person",
-                             :id "http://sally.example.org",
-                             :summary "Sally"}))
+  (is (s/valid? ::sut/actor {::sut/type "Person",
+                             ::sut/id "http://sally.example.org",
+                             ::sut/summary "Sally"}))
   (is (s/valid? ::sut/actor ["http://joe.example.org",
-                             {:type "Person",
-                              :id "http://sally.example.org",
-                              :name "Sally"}])))
+                             {::sut/type "Person",
+                              ::sut/id "http://sally.example.org",
+                              ::sut/name "Sally"}])))
 
 (deftest bcc-test
   (is (s/valid? ::sut/bcc ["http://joe.example.org"])))
@@ -70,34 +70,34 @@
 
 (deftest Activity-test
   (is (s/valid? ::sut/Activity
-                {:type "Activity",
-                 :summary "Sally did something to a note",
-                 :actor {:type "Person",
-                         :name "Sally"},
-                 :object {:type "Note",
-                          :name "A Note"}})))
+                {::sut/type "Activity",
+                 ::sut/summary "Sally did something to a note",
+                 ::sut/actor {::sut/type "Person",
+                         ::sut/name "Sally"},
+                 ::sut/object {::sut/type "Note",
+                          ::sut/name "A Note"}})))
 
 (deftest Like-test
   (is (s/valid? ::sut/Like 
-                {:summary "Sally liked a note",
-                 :type "Like",
-                 :actor {:type "Person",
-                         :name "Sally"},
-                 :object "http://example.org/notes/1"}))
+                {::sut/summary "Sally liked a note",
+                 ::sut/type "Like",
+                 ::sut/actor {::sut/type "Person",
+                         ::sut/name "Sally"},
+                 ::sut/object "http://example.org/notes/1"}))
   (is (s/valid? ::sut/Like
-                {:id "foo",
-                 :type "Like",
-                 :actor "https://social.bla/alyssa",
-                 :object "http://example.org/notes/1"})))
+                {::sut/id "foo",
+                 ::sut/type "Like",
+                 ::sut/actor "https://social.bla/alyssa",
+                 ::sut/object "http://example.org/notes/1"})))
 
 (deftest Object-test
   (is (s/valid? ::sut/Object
-                {:summary "Sally liked a note",
-                 :type "Like",
-                 :actor {:type "Person",
-                         :name "Sally"},
-                 :object "http://example.org/notes/1"}))
+                {::sut/summary "Sally liked a note",
+                 ::sut/type "Like",
+                 ::sut/actor {::sut/type "Person",
+                         ::sut/name "Sally"},
+                 ::sut/object "http://example.org/notes/1"}))
   (is (s/valid? ::sut/Object
-                {:type "Object",
-                 :id "http://www.test.example/object/1",
-                 :name "A Simple, non-specific object"})))
+                {::sut/type "Object",
+                 ::sut/id "http://www.test.example/object/1",
+                 ::sut/name "A Simple, non-specific object"})))