diff --git a/posts/studycase2.md b/posts/studycase2.md
index 5bbfed2..fb078bc 100644
--- a/posts/studycase2.md
+++ b/posts/studycase2.md
@@ -156,11 +156,11 @@ namespace StudyCase2
             moveDir = forward.TransformDirection(moveDir);
             if (moveInput != Vector2.zero)
             {
-                animator?.SetBool("Move", true);
+                animator.SetBool("Move", true);
                 Quaternion target = Quaternion.LookRotation(new Vector3(moveDir.x, 0, moveDir.z));
                 model.rotation = Quaternion.Slerp(model.rotation, target, turnSpeed * Time.deltaTime);
             }
-            else animator?.SetBool("Move", false);
+            else animator.SetBool("Move", false);
             if (!characterController.isGrounded)
                 moveDir.y -= gravity * Time.deltaTime;
             characterController.Move(moveDir * moveSpeed * Time.deltaTime);
diff --git a/posts/studycase3.md b/posts/studycase3.md
index de2eda5..b415847 100644
--- a/posts/studycase3.md
+++ b/posts/studycase3.md
@@ -205,11 +205,11 @@ namespace StudyCase3
             moveDir = forward.TransformDirection(moveDir);
             if (moveInput != Vector2.zero)
             {
-                animator?.SetBool("Move", true);
+                animator.SetBool("Move", true);
                 Quaternion target = Quaternion.LookRotation(new Vector3(moveDir.x, 0, moveDir.z));
                 model.rotation = Quaternion.Slerp(model.rotation, target, turnSpeed * Time.deltaTime);
             }
-            else animator?.SetBool("Move", false);
+            else animator.SetBool("Move", false);
             if (!characterController.isGrounded)
                 moveDir.y -= gravity * Time.deltaTime;
             characterController.Move(moveDir * moveSpeed * Time.deltaTime);