diff --git a/src/Internal/Values/Event.elm b/src/Internal/Values/Event.elm
index 61414f9..e0ad27f 100644
--- a/src/Internal/Values/Event.elm
+++ b/src/Internal/Values/Event.elm
@@ -1,7 +1,7 @@
 module Internal.Values.Event exposing
     ( Event
     , content, eventId, eventType, originServerTs, roomId, sender, stateKey
-    , UnsignedData, age, prevContent, redactedBecause, transactionId
+    , UnsignedData(..), age, prevContent, redactedBecause, transactionId
     , encode, decoder
     )
 
diff --git a/tests/Event.elm b/tests/Event.elm
new file mode 100644
index 0000000..f7be57c
--- /dev/null
+++ b/tests/Event.elm
@@ -0,0 +1,84 @@
+module Event exposing (..)
+
+import Expect
+import Fuzz exposing (Fuzzer)
+import Iddict as TestIddict
+import Internal.Tools.Iddict as Iddict
+import Internal.Tools.Timestamp as Timestamp
+import Internal.Values.Envelope as Envelope
+import Internal.Values.Event as Event
+import Json.Decode as D
+import Json.Encode as E
+import Test exposing (..)
+import Timestamp as TestTimestamp
+
+
+{-| Example values that can be used for arbitrary JSON values
+-}
+valueFuzzer : Fuzzer E.Value
+valueFuzzer =
+    Fuzz.oneOf
+        [ Fuzz.map (Iddict.encode E.int) (TestIddict.fuzzer Fuzz.int)
+        , Fuzz.map Timestamp.encode TestTimestamp.fuzzer
+        , Fuzz.map E.int Fuzz.int
+        , Fuzz.map E.string Fuzz.string
+        , Fuzz.map (E.list E.int) (Fuzz.list Fuzz.int)
+        , Fuzz.map (E.list E.string) (Fuzz.list Fuzz.string)
+        , Fuzz.map Event.encode (Fuzz.lazy (\_ -> fuzzer))
+        ]
+
+
+fuzzer : Fuzzer Event.Event
+fuzzer =
+    Fuzz.map8
+        (\c ei et o r se sk u ->
+            Envelope.init
+                { content = c
+                , eventId = ei
+                , eventType = et
+                , originServerTs = o
+                , roomId = r
+                , sender = se
+                , stateKey = sk
+                , unsigned = u
+                }
+        )
+        valueFuzzer
+        Fuzz.string
+        Fuzz.string
+        TestTimestamp.fuzzer
+        Fuzz.string
+        Fuzz.string
+        (Fuzz.maybe Fuzz.string)
+        (Fuzz.maybe unsignedDataFuzzer)
+
+
+unsignedDataFuzzer : Fuzzer Event.UnsignedData
+unsignedDataFuzzer =
+    Fuzz.map4
+        (\age prev redact trans ->
+            Event.UnsignedData
+                { age = age
+                , prevContent = prev
+                , redactedBecause = redact
+                , transactionId = trans
+                }
+        )
+        (Fuzz.maybe Fuzz.int)
+        (Fuzz.maybe valueFuzzer)
+        (Fuzz.maybe <| Fuzz.lazy (\_ -> fuzzer))
+        (Fuzz.maybe Fuzz.string)
+
+
+json : Test
+json =
+    describe "JSON tests"
+        [ fuzz fuzzer
+            "JSON encode + JSON decode"
+            (\event ->
+                event
+                    |> Event.encode
+                    |> D.decodeValue Event.decoder
+                    |> Expect.equal (Ok event)
+            )
+        ]
diff --git a/tests/Timestamp.elm b/tests/Timestamp.elm
new file mode 100644
index 0000000..f8b7dd4
--- /dev/null
+++ b/tests/Timestamp.elm
@@ -0,0 +1,11 @@
+module Timestamp exposing (..)
+
+import Fuzz exposing (Fuzzer)
+import Internal.Tools.Timestamp exposing (Timestamp)
+import Test exposing (..)
+import Time
+
+
+fuzzer : Fuzzer Timestamp
+fuzzer =
+    Fuzz.map Time.millisToPosix Fuzz.int