diff --git a/src/main/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/SnowplowEvent.scala b/src/main/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/SnowplowEvent.scala
index 84435d5..db2c4e3 100644
--- a/src/main/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/SnowplowEvent.scala
+++ b/src/main/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/SnowplowEvent.scala
@@ -61,15 +61,18 @@ object SnowplowEvent {
   case class Contexts(data: List[SelfDescribingData[Json]]) extends AnyVal {
     def toShreddedJson: Map[String, Json] =
       data.groupBy(x => (x.schema.vendor, x.schema.name, x.schema.format, x.schema.version.model)).map {
-        case ((vendor, name, _, model), d) =>
-          (transformSchema(Data.Contexts(Data.CustomContexts), vendor, name, model),
-           d.map { selfdesc =>
-             selfdesc.data
-           }.asJson
-          )
+        case ((vendor, name, _, model), contextsSdd) =>
+          val transformedName = transformSchema(Data.Contexts(Data.CustomContexts), vendor, name, model)
+          val transformedData = contextsSdd.map(addSchemaVersionToData).asJson
+          (transformedName, transformedData)
       }
   }
 
+  private def addSchemaVersionToData(contextSdd: SelfDescribingData[Json]): Json = {
+    val version = Json.obj("_schema_version" -> contextSdd.schema.toSchemaUri.asJson)
+    contextSdd.data.deepMerge(version)
+  }
+
   implicit final val contextsCirceEncoder: Encoder[Contexts] =
     Encoder.instance { contexts =>
       if (contexts.data.isEmpty) JsonObject.empty.asJson
diff --git a/src/test/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/EventSpec.scala b/src/test/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/EventSpec.scala
index 1f6674f..c3b24c9 100644
--- a/src/test/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/EventSpec.scala
+++ b/src/test/scala/com.snowplowanalytics.snowplow.analytics.scalasdk/EventSpec.scala
@@ -224,6 +224,7 @@ class EventSpec extends Specification with ScalaCheck {
         "mkt_content" : null,
         "mkt_campaign" : null,
         "contexts_org_schema_web_page_1" : [ {
+          "_schema_version" : "iglu:org.schema/WebPage/jsonschema/1-0-0",
           "genre" : "blog",
           "inLanguage" : "en-US",
           "datePublished" : "2014-11-06T00:00:00Z",
@@ -232,6 +233,7 @@ class EventSpec extends Specification with ScalaCheck {
           "keywords" : [ "snowplow", "javascript", "tracker", "event" ]
         } ],
         "contexts_org_w3_performance_timing_1" : [ {
+          "_schema_version" : "iglu:org.w3/PerformanceTiming/jsonschema/1-0-0",
           "navigationStart" : 1415358089861,
           "unloadEventStart" : 1415358090270,
           "unloadEventEnd" : 1415358090287,
@@ -327,6 +329,7 @@ class EventSpec extends Specification with ScalaCheck {
         "refr_domain_userid" : null,
         "refr_dvce_tstamp" : null,
         "contexts_com_snowplowanalytics_snowplow_ua_parser_context_1": [{
+          "_schema_version" : "iglu:com.snowplowanalytics.snowplow/ua_parser_context/jsonschema/1-0-0",
           "useragentFamily": "IE",
           "useragentMajor": "7",
           "useragentMinor": "0",
@@ -663,6 +666,7 @@ class EventSpec extends Specification with ScalaCheck {
         "mkt_content" : null,
         "mkt_campaign" : null,
         "contexts_org_schema_web_page_1" : [ {
+          "_schema_version" : "iglu:org.schema/WebPage/jsonschema/1-0-0",
           "genre" : "blog",
           "inLanguage" : "en-US",
           "datePublished" : "2014-11-06T00:00:00Z",
@@ -672,9 +676,11 @@ class EventSpec extends Specification with ScalaCheck {
         } ],
         "contexts_org_acme_context_one_1" : [
           {
+            "_schema_version" : "iglu:org.acme/context_one/jsonschema/1-0-0",
             "item" : 1
           },
           {
+            "_schema_version" : "iglu:org.acme/context_one/jsonschema/1-0-1",
             "item" : 2
           }
         ],
@@ -752,6 +758,7 @@ class EventSpec extends Specification with ScalaCheck {
         "refr_domain_userid" : null,
         "refr_dvce_tstamp" : null,
         "contexts_com_snowplowanalytics_snowplow_ua_parser_context_1": [{
+          "_schema_version" : "iglu:com.snowplowanalytics.snowplow/ua_parser_context/jsonschema/1-0-0",
           "useragentFamily": "IE",
           "useragentMajor": "7",
           "useragentMinor": "0",
@@ -794,6 +801,7 @@ class EventSpec extends Specification with ScalaCheck {
         "contexts_org_schema_web_page_1" ->
           List(
             JsonObject(
+              ("_schema_version", "iglu:org.schema/WebPage/jsonschema/1-0-0".asJson),
               ("genre", "blog".asJson),
               ("inLanguage", "en-US".asJson),
               ("datePublished", "2014-11-06T00:00:00Z".asJson),
@@ -805,9 +813,11 @@ class EventSpec extends Specification with ScalaCheck {
         "contexts_org_acme_context_one_1" ->
           List(
             JsonObject(
+              ("_schema_version", "iglu:org.acme/context_one/jsonschema/1-0-0".asJson),
               ("item", 1.asJson)
             ).asJson,
             JsonObject(
+              ("_schema_version", "iglu:org.acme/context_one/jsonschema/1-0-1".asJson),
               ("item", 2.asJson)
             ).asJson
           ).asJson
@@ -816,6 +826,7 @@ class EventSpec extends Specification with ScalaCheck {
         "contexts_com_snowplowanalytics_snowplow_ua_parser_context_1" ->
           List(
             JsonObject(
+              ("_schema_version", "iglu:com.snowplowanalytics.snowplow/ua_parser_context/jsonschema/1-0-0".asJson),
               ("useragentFamily", "IE".asJson),
               ("useragentMajor", "7".asJson),
               ("useragentMinor", "0".asJson),