diff --git a/src/GitHub/Data/Issues.hs b/src/GitHub/Data/Issues.hs
index cb3981fb..82c0324d 100644
--- a/src/GitHub/Data/Issues.hs
+++ b/src/GitHub/Data/Issues.hs
@@ -13,7 +13,7 @@ import GitHub.Data.Options      (IssueState)
 import GitHub.Data.PullRequests
 import GitHub.Data.URL          (URL)
 import GitHub.Internal.Prelude
-import Prelude ()
+import Prelude                  ()
 
 data Issue = Issue
     { issueClosedAt    :: !(Maybe UTCTime)
@@ -43,7 +43,7 @@ instance Binary Issue
 data NewIssue = NewIssue
     { newIssueTitle     :: !Text
     , newIssueBody      :: !(Maybe Text)
-    , newIssueAssignee  :: !(Maybe Text)
+    , newIssueAssignees :: !(Vector (Name User))
     , newIssueMilestone :: !(Maybe (Id Milestone))
     , newIssueLabels    :: !(Maybe (Vector (Name IssueLabel)))
     }
@@ -55,7 +55,7 @@ instance Binary NewIssue
 data EditIssue = EditIssue
     { editIssueTitle     :: !(Maybe Text)
     , editIssueBody      :: !(Maybe Text)
-    , editIssueAssignee  :: !(Maybe (Name User))
+    , editIssueAssignees :: !(Maybe (Vector (Name User)))
     , editIssueState     :: !(Maybe IssueState)
     , editIssueMilestone :: !(Maybe (Id Milestone))
     , editIssueLabels    :: !(Maybe (Vector (Name IssueLabel)))
@@ -203,19 +203,22 @@ instance FromJSON Issue where
         <*> o .:? "milestone"
 
 instance ToJSON NewIssue where
-    toJSON (NewIssue t b a m ls) = object
+    toJSON (NewIssue t b a m ls) = object $ filter notNull
         [ "title"     .= t
         , "body"      .= b
-        , "assignee"  .= a
+        , "assignees" .= a
         , "milestone" .= m
         , "labels"    .= ls
         ]
+      where
+        notNull (_, Null) = False
+        notNull (_, _)    = True
 
 instance ToJSON EditIssue where
-    toJSON (EditIssue t b a s m ls) = object $ filter notNull $
+    toJSON (EditIssue t b a s m ls) = object $ filter notNull
         [ "title"     .= t
         , "body"      .= b
-        , "assignee"  .= a
+        , "assignees" .= a
         , "state"     .= s
         , "milestone" .= m
         , "labels"    .= ls
diff --git a/src/GitHub/Endpoints/Issues.hs b/src/GitHub/Endpoints/Issues.hs
index 431e1c3e..7b2c5c43 100644
--- a/src/GitHub/Endpoints/Issues.hs
+++ b/src/GitHub/Endpoints/Issues.hs
@@ -85,7 +85,7 @@ issuesForRepoR user reqRepoName opts =
 -- Creating new issues.
 
 newIssue :: Text -> NewIssue
-newIssue title = NewIssue title Nothing Nothing Nothing Nothing
+newIssue title = NewIssue title Nothing mempty Nothing Nothing
 
 
 -- | Create a new issue.