diff --git a/repo_collaborator.go b/repo_collaborator.go
index c382bc7..6030850 100644
--- a/repo_collaborator.go
+++ b/repo_collaborator.go
@@ -29,7 +29,7 @@ func (c *Client) AddCollaborator(user, repo, collaborator string, opt AddCollabo
 	if err != nil {
 		return err
 	}
-	_, err = c.getResponse("PUT", fmt.Sprintf("/repos/%s/%s/collaborators/%s", user, repo, collaborator), nil, bytes.NewReader(body))
+	_, err = c.getResponse("PUT", fmt.Sprintf("/repos/%s/%s/collaborators/%s", user, repo, collaborator), jsonHeader, bytes.NewReader(body))
 	return err
 }
 
diff --git a/user_follow.go b/user_follow.go
index 36cc65d..5ba20cc 100644
--- a/user_follow.go
+++ b/user_follow.go
@@ -37,7 +37,7 @@ func (c *Client) IsUserFollowing(user, target string) bool {
 }
 
 func (c *Client) Follow(target string) error {
-	_, err := c.getResponse("PUT", fmt.Sprintf("/user/following/%s", target), nil, nil)
+	_, err := c.getResponse("PUT", fmt.Sprintf("/user/following/%s", target), jsonHeader, nil)
 	return err
 }