diff --git a/app/src/main/java/com/example/tampopo_client/resources/ActivitiesResource.java b/app/src/main/java/com/example/tampopo_client/resources/ActivitiesResource.java
index 7df8292..c30407e 100644
--- a/app/src/main/java/com/example/tampopo_client/resources/ActivitiesResource.java
+++ b/app/src/main/java/com/example/tampopo_client/resources/ActivitiesResource.java
@@ -31,8 +31,8 @@
     Call<String> getText(@Path("user_id") String userId, @Path("activity_id") String activityId);
 
     @GET("users/{user_id}/activities/{activity_id}/updated-time")
-    Call<Activity> getUpdatedTime(@Path("user_id") String userId, @Path("activity_id") String activityId);
+    Call<String> getUpdatedTime(@Path("user_id") String userId, @Path("activity_id") String activityId);
 
     @GET("users/{user_id}/activities/last-updated-time")
-    Call<Activity> getLastUpdatedTime(@Path("user_id") String userId, @Path("activity_id") String activityId);
+    Call<String> getLastUpdatedTime(@Path("user_id") String userId, @Path("activity_id") String activityId);
 }