diff --git a/src/main/java/be/cytomine/api/controller/image/RestSliceInstanceController.java b/src/main/java/be/cytomine/api/controller/image/RestSliceInstanceController.java
index 9ae484ca..395ecdb4 100644
--- a/src/main/java/be/cytomine/api/controller/image/RestSliceInstanceController.java
+++ b/src/main/java/be/cytomine/api/controller/image/RestSliceInstanceController.java
@@ -92,6 +92,7 @@ private JsonObject addToken(SliceInstance sliceInstance) {
         String token = (String) tokenData.get("token");
         Instant expiryTime = (Instant) tokenData.get("expiryTime");
         returnArray.put("temporaryToken", token);
+        returnArray.put("tokenExpiryTime", expiryTime.getEpochSecond());
         return returnArray;
     }