diff --git a/backend/src/main/java/core/api/controller/TaskController.java b/backend/src/main/java/core/api/controller/TaskController.java
index f47aeeb..0d814f0 100644
--- a/backend/src/main/java/core/api/controller/TaskController.java
+++ b/backend/src/main/java/core/api/controller/TaskController.java
@@ -109,7 +109,7 @@ public class TaskController {
             return ResponseEntity.status(404).body(new SimpleStatusResponse("failed"));
         }
 
-        if(taskFieldInfo.getStartDate().isAfter(taskFieldInfo.getDeadline())) {
+        if(taskFieldInfo.getStartDate() != null && taskFieldInfo.getDeadline() != null && taskFieldInfo.getStartDate().isAfter(taskFieldInfo.getDeadline())) {
             return ResponseEntity.status(400).body(new SimpleStatusResponse("failed"));
         }