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 251f301..cd86a21 100644
--- a/src/main/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2.cljc
+++ b/src/main/cljc/org/domaindrivenarchitecture/activity_pub_poc/activitystreams2.cljc
@@ -88,7 +88,9 @@
 ;https://www.w3.org/TR/activitystreams-vocabulary/#dfn-type
 ;TODO: this can not be found in the ttl / namespace. Where is this exactly defined?
 (s/def ::type
-  ::xsd/anyURI)
+  (s/or
+   :single-value ::xsd/anyURI
+   :coll-of-values (s/+ ::xsd/anyURI)))
 
 ;http://www.w3.org/ns/activitystreams#result
 (s/def ::result 
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 a69ee36..8414306 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
@@ -12,6 +12,18 @@
   (is (not (s/valid? ::sut/id "https://no-uri:abc")))
   (is (not (s/valid? ::sut/id ["https://social.bla/alyssa/status/RANDOMHASH", "https://social.bla/alyssa/status/RANDOMHASH2"]))))
 
+
+(deftest type-test
+  (is (s/valid? ::sut/type "https://social.bla/alyssa/status/RANDOMHASH"))
+  (is (s/valid? ::sut/type "Activity"))
+  (is (s/valid? ::sut/type "Activity"))
+  (is (s/valid? ::sut/type ["https://social.bla/alyssa/status/RANDOMHASH", "https://social.bla/alyssa/status/RANDOMHASH2"]))
+  (is (not (s/valid? ::sut/type nil)))
+  (is (not (s/valid? ::sut/type [])))
+  (is (not (s/valid? ::sut/type 2)))
+  (is (not (s/valid? ::sut/type "https://no-uri:abc")))
+  )
+
 (deftest object-test
   (is (s/valid? ::sut/object "http://example.org/posts/1"))
   (is (s/valid? ::sut/object {:type "Note",