diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,11 @@
 
+50200.13.0
+==========
+
+API changes:
+ * Added a `wepParentId` field to `WEData` and parsed `parent_id` in its
+   JSON representation.
+
 50200.12.0
 ==========
 
diff --git a/mattermost-api.cabal b/mattermost-api.cabal
--- a/mattermost-api.cabal
+++ b/mattermost-api.cabal
@@ -1,5 +1,5 @@
 name:                mattermost-api
-version:             50200.12.0
+version:             50200.13.0
 synopsis:            Client API for Mattermost chat system
 
 description:         Client API for Mattermost chat system.  Mattermost is a
diff --git a/src/Network/Mattermost/WebSocket/Types.hs b/src/Network/Mattermost/WebSocket/Types.hs
--- a/src/Network/Mattermost/WebSocket/Types.hs
+++ b/src/Network/Mattermost/WebSocket/Types.hs
@@ -203,6 +203,7 @@
   , wepTeamId             :: Maybe TeamId
   , wepSenderName         :: Maybe Text
   , wepUserId             :: Maybe UserId
+  , wepParentId           :: Maybe PostId
   , wepUser               :: Maybe User
   , wepChannelDisplayName :: Maybe Text
   , wepPost               :: Maybe Post
@@ -219,6 +220,7 @@
     wepTeamId             <- maybeFail (o .: "team_id")
     wepSenderName         <- o .:? "sender_name"
     wepUserId             <- o .:? "user_id"
+    wepParentId           <- nullable (o .: "parent_id")
     wepUser               <- o .:? "user"
     wepChannelDisplayName <- o .:? "channel_name"
     wepPost               <- mapM fromValueString =<< o .:? "post"
@@ -235,6 +237,7 @@
     , "team_id"      .= wepTeamId
     , "sender_name"  .= wepSenderName
     , "user_id"      .= wepUserId
+    , "parent_id"    .= wepParentId
     , "channel_name" .= wepChannelDisplayName
     , "post"         .= toValueString wepPost
     , "reaction"     .= wepReaction