diff --git a/search.go b/search.go
index 0b2fa54..1182bb6 100644
--- a/search.go
+++ b/search.go
@@ -7,17 +7,19 @@ import (
 
 type SearchOpts struct {
 	Query       string        `json:"query,omitempty"`
-	Sort        *SearchFilter `json:"sort,omitempty"`
+	Sort        *SearchSort   `json:"sort,omitempty"`
 	Filter      *SearchFilter `json:"filter,omitempty"`
 	StartCursor string        `json:"start_cursor,omitempty"`
 	PageSize    int           `json:"page_size,omitempty"`
 }
 
 type SearchSort struct {
-	Direction SortDirection `json:"direction,omitempty"`
-	Timestamp string        `json:"timestamp"`
+	Direction SortDirection       `json:"direction,omitempty"`
+	Timestamp SearchSortTimestamp `json:"timestamp"`
 }
 
+type SearchSortTimestamp string
+
 type SearchFilter struct {
 	Value    string `json:"value"`
 	Property string `json:"property"`
@@ -32,6 +34,8 @@ type SearchResponse struct {
 
 type SearchResults []interface{}
 
+const SearchSortTimestampLastEditedTime SearchSortTimestamp = "last_edited_time"
+
 func (sr *SearchResults) UnmarshalJSON(b []byte) error {
 	rawResults := []json.RawMessage{}
 	err := json.Unmarshal(b, &rawResults)