diff --git a/lib/edge/targeting.ts b/lib/edge/targeting.ts
index a3996b9..29cc10f 100644
--- a/lib/edge/targeting.ts
+++ b/lib/edge/targeting.ts
@@ -36,6 +36,8 @@ type TargetingResponse = {
   resolved_ids?: string[];
   // A/B test ID
   ab_test_id?: string;
+  // Split test Assignment
+  split_test_assignment?: string;
 };
 
 // Determine which A/B test (if any) should be used for this request