diff --git a/src/xapi_schema/spec.cljc b/src/xapi_schema/spec.cljc
index 05c351f..9757d79 100644
--- a/src/xapi_schema/spec.cljc
+++ b/src/xapi_schema/spec.cljc
@@ -281,10 +281,7 @@
   (s/with-gen
     (s/and string?
            (partial re-matches xAPIVersionRegEx))
-    #(sgen/fmap (fn [i]
-                  (#?(:clj format
-                      :cljs gstring/format) "1.0.%d" i))
-                (sgen/int))))
+    #(sgen/return "2.0.0")))
 
 (s/def ::sha2
   (s/with-gen
@@ -815,17 +812,17 @@
     (-> scores
         (assoc :score/min raw)
         (assoc :score/raw min))
-    
+
     (and min max (< max min))
     (-> scores
         (assoc :score/min max)
         (assoc :score/max min))
-    
+
     (and raw max (< max raw))
     (-> scores
         (assoc :score/raw max)
         (assoc :score/max raw))
-    
+
     :else
     scores))
 
@@ -973,6 +970,51 @@
 (s/def :context/extensions
   ::extensions)
 
+;; 2.0.x compat
+
+;; contextAgents
+(s/def :contextAgent/objectType #{"contextAgent"})
+(s/def :contextAgent/agent ::agent)
+(s/def :contextAgent/relevantTypes
+  (s/every ::iri
+           :into []
+           :min-count 1))
+
+(s/def ::context-agent
+  (conform-ns "contextAgent"
+              (s/and
+               (s/keys :req [:contextAgent/objectType
+                             :contextAgent/agent]
+                       :opt [:contextAgent/relevantTypes])
+               (restrict-keys :contextAgent/objectType
+                              :contextAgent/agent
+                              :contextAgent/relevantTypes))))
+(s/def :context/contextAgents
+  (s/every ::context-agent
+           :into []))
+
+;; contextGroups
+
+(s/def :contextGroup/objectType #{"contextGroup"})
+(s/def :contextGroup/group ::group)
+(s/def :contextGroup/relevantTypes
+  (s/every ::iri
+           :into []
+           :min-count 1))
+
+(s/def ::context-group
+  (conform-ns "contextGroup"
+              (s/and
+               (s/keys :req [:contextGroup/objectType
+                             :contextGroup/group]
+                       :opt [:contextGroup/relevantTypes])
+               (restrict-keys :contextGroup/objectType
+                              :contextGroup/group
+                              :contextGroup/relevantTypes))))
+(s/def :context/contextGroups
+  (s/every ::context-group
+           :into []))
+
 (s/def ::context
   (conform-ns "context"
               (s/and
@@ -984,7 +1026,9 @@
                              :context/platform
                              :context/language
                              :context/statement
-                             :context/extensions])
+                             :context/extensions
+                             :context/contextAgents
+                             :context/contextGroups])
                (restrict-keys :context/registration
                               :context/instructor
                               :context/team
@@ -993,7 +1037,9 @@
                               :context/platform
                               :context/language
                               :context/statement
-                              :context/extensions))))
+                              :context/extensions
+                              :context/contextAgents
+                              :context/contextGroups))))
 
 ;; Attachments
 
@@ -1326,8 +1372,19 @@
                    (some-> s :statement/object :statement-ref/objectType)
                    true)))))
 
+(defn unique-statement-ids?
+  "Spec predicate to ensure that the IDs of a list of statements are unique."
+  [statements]
+  (let [ids (keep #(get % "id") statements)]
+    (or
+     (empty? ids)
+     (reduce distinct? ids)
+     ::s/invalid)))
+
 (s/def ::statements
-  (s/coll-of ::statement :into []))
+  (s/and
+   (s/coll-of ::statement :into [])
+   unique-statement-ids?))
 
 (s/def ::lrs-statements
   (s/coll-of ::lrs-statement :into []))
diff --git a/src/xapi_schema/spec/regex.cljc b/src/xapi_schema/spec/regex.cljc
index f0165d9..fc57e1a 100644
--- a/src/xapi_schema/spec/regex.cljc
+++ b/src/xapi_schema/spec/regex.cljc
@@ -117,7 +117,7 @@
         ;; Time
         time (str "(?:" hour ":" min ":" sec sec-frac "?" ")")
         date (str "(?:" year "-" month "-" day ")")]
-    (str date "T" time)))
+    (str date "[T\\s]" time)))
 
 (def TimestampRegEx ; RFC 3339
   (let [;; Time
@@ -148,7 +148,7 @@
 (def xAPIVersionRegEx
   (let [suf-part "[0-9a-zA-Z-]+(?:\\.[0-9a-zA-Z-]+)*"
         suffix   (str "(\\.[0-9]+(?:-" suf-part ")?(?:\\+" suf-part ")?)?")
-        ver-str  (str "^1\\.0" suffix "$")]
+        ver-str  (str "^(1\\.0" suffix ")|(2\\.0\\.0)$")]
     (re-pattern ver-str)))
 
 (def Base64RegEx
diff --git a/test/xapi_schema/spec/regex_test.cljc b/test/xapi_schema/spec/regex_test.cljc
index 048d57a..c2356e4 100644
--- a/test/xapi_schema/spec/regex_test.cljc
+++ b/test/xapi_schema/spec/regex_test.cljc
@@ -145,7 +145,9 @@
     (is (not (re-matches TimestampRegEx "20150513T15Z")))
     (is (not (re-matches TimestampRegEx "20150513T15:16:00Z")))
     ;; negative offset
-    (is (not (re-matches TimestampRegEx "2008-09-15T15:53:00.601-00:00")))))
+    (is (not (re-matches TimestampRegEx "2008-09-15T15:53:00.601-00:00"))))
+  (testing "matches valid but terrible stamps in rfc3339 OUTSIDE of 8601"
+    (is (re-matches TimestampRegEx "2015-05-13 15:16:00Z"))))
 
 (deftest xapi-version-regex-test
   (testing "matches xAPI 1.0.X versions"
@@ -153,7 +155,10 @@
              (re-matches xAPIVersionRegEx "1.0.2")
              (re-matches xAPIVersionRegEx "1.0")
              (re-matches xAPIVersionRegEx "1.0.32-abc.def+ghi.jkl")))
-    (is (not (re-matches xAPIVersionRegEx "0.9.5")))))
+    (is (not (re-matches xAPIVersionRegEx "0.9.5"))))
+  (testing "matches xAPI 2.0.0 version only"
+    (is (and (re-matches xAPIVersionRegEx "2.0.0")
+             (not (re-matches xAPIVersionRegEx "2.0.2"))))))
 
 (deftest duration-regex-test
   (testing "matches ISO durations"