diff --git a/openstack/identity/v2/users/requests.go b/openstack/identity/v2/users/requests.go
index 7fa5fc3..f62f979 100644
--- a/openstack/identity/v2/users/requests.go
+++ b/openstack/identity/v2/users/requests.go
@@ -7,41 +7,25 @@
 
 // List lists the existing users.
 func List(client *gophercloud.ServiceClient) pagination.Pager {
-	createPage := func(r pagination.PageResult) pagination.Page {
+	return pagination.NewPager(client, rootURL(client), func(r pagination.PageResult) pagination.Page {
 		return UserPage{pagination.SinglePageBase(r)}
-	}
-
-	return pagination.NewPager(client, rootURL(client), createPage)
+	})
 }
 
-// EnabledState represents whether the user is enabled or not.
-type EnabledState *bool
-
-// Useful variables to use when creating or updating users.
-var (
-	iTrue  = true
-	iFalse = false
-
-	Enabled  EnabledState = &iTrue
-	Disabled EnabledState = &iFalse
-)
-
 // CommonOpts are the parameters that are shared between CreateOpts and
 // UpdateOpts
 type CommonOpts struct {
 	// Either a name or username is required. When provided, the value must be
 	// unique or a 409 conflict error will be returned. If you provide a name but
 	// omit a username, the latter will be set to the former; and vice versa.
-	Name, Username string
-
+	Name     string `json:"name,omitempty"`
+	Username string `json:"username,omitempty"`
 	// The ID of the tenant to which you want to assign this user.
-	TenantID string
-
+	TenantID string `json:"tenant_id,omitempty"`
 	// Indicates whether this user is enabled or not.
-	Enabled EnabledState
-
+	Enabled *bool `json:"enabled,omitempty"`
 	// The email address of this user.
-	Email string
+	Email string `json:"email,omitempty"`
 }
 
 // CreateOpts represents the options needed when creating new users.
@@ -54,33 +38,13 @@
 
 // ToUserCreateMap assembles a request body based on the contents of a CreateOpts.
 func (opts CreateOpts) ToUserCreateMap() (map[string]interface{}, error) {
-	m := make(map[string]interface{})
-
 	if opts.Name == "" && opts.Username == "" {
 		err := gophercloud.ErrMissingInput{}
-		err.Function = "users.ToUserCreateMap"
 		err.Argument = "users.CreateOpts.Name/users.CreateOpts.Username"
 		err.Info = "Either a Name or Username must be provided"
-		return m, err
+		return nil, err
 	}
-
-	if opts.Name != "" {
-		m["name"] = opts.Name
-	}
-	if opts.Username != "" {
-		m["username"] = opts.Username
-	}
-	if opts.Enabled != nil {
-		m["enabled"] = &opts.Enabled
-	}
-	if opts.Email != "" {
-		m["email"] = opts.Email
-	}
-	if opts.TenantID != "" {
-		m["tenant_id"] = opts.TenantID
-	}
-
-	return map[string]interface{}{"user": m}, nil
+	return gophercloud.BuildRequestBody(opts, "user")
 }
 
 // Create is the operation responsible for creating new users.
@@ -109,57 +73,41 @@
 
 // UpdateOptsBuilder allows extensions to add additional attributes to the Update request.
 type UpdateOptsBuilder interface {
-	ToUserUpdateMap() map[string]interface{}
+	ToUserUpdateMap() (map[string]interface{}, error)
 }
 
 // UpdateOpts specifies the base attributes that may be updated on an existing server.
 type UpdateOpts CommonOpts
 
 // ToUserUpdateMap formats an UpdateOpts structure into a request body.
-func (opts UpdateOpts) ToUserUpdateMap() map[string]interface{} {
-	m := make(map[string]interface{})
-
-	if opts.Name != "" {
-		m["name"] = opts.Name
-	}
-	if opts.Username != "" {
-		m["username"] = opts.Username
-	}
-	if opts.Enabled != nil {
-		m["enabled"] = &opts.Enabled
-	}
-	if opts.Email != "" {
-		m["email"] = opts.Email
-	}
-	if opts.TenantID != "" {
-		m["tenant_id"] = opts.TenantID
-	}
-
-	return map[string]interface{}{"user": m}
+func (opts UpdateOpts) ToUserUpdateMap() (map[string]interface{}, error) {
+	return gophercloud.BuildRequestBody(opts, "user")
 }
 
 // Update is the operation responsible for updating exist users by their UUID.
 func Update(client *gophercloud.ServiceClient, id string, opts UpdateOptsBuilder) UpdateResult {
-	var result UpdateResult
-	reqBody := opts.ToUserUpdateMap()
-	_, result.Err = client.Put(ResourceURL(client, id), reqBody, &result.Body, &gophercloud.RequestOpts{
+	var r UpdateResult
+	b, err := opts.ToUserUpdateMap()
+	if err != nil {
+		r.Err = err
+		return r
+	}
+	_, r.Err = client.Put(ResourceURL(client, id), &b, &r.Body, &gophercloud.RequestOpts{
 		OkCodes: []int{200},
 	})
-	return result
+	return r
 }
 
 // Delete is the operation responsible for permanently deleting an API user.
 func Delete(client *gophercloud.ServiceClient, id string) DeleteResult {
-	var result DeleteResult
-	_, result.Err = client.Delete(ResourceURL(client, id), nil)
-	return result
+	var r DeleteResult
+	_, r.Err = client.Delete(ResourceURL(client, id), nil)
+	return r
 }
 
 // ListRoles lists the existing roles that can be assigned to users.
 func ListRoles(client *gophercloud.ServiceClient, tenantID, userID string) pagination.Pager {
-	createPage := func(r pagination.PageResult) pagination.Page {
+	return pagination.NewPager(client, listRolesURL(client, tenantID, userID), func(r pagination.PageResult) pagination.Page {
 		return RolePage{pagination.SinglePageBase(r)}
-	}
-
-	return pagination.NewPager(client, listRolesURL(client, tenantID, userID), createPage)
+	})
 }