diff --git a/app/src/main/java/org/ntlab/acanthus_client/Acanthus.java b/app/src/main/java/org/ntlab/acanthus_client/Acanthus.java
index 5331097..4cf6c47 100644
--- a/app/src/main/java/org/ntlab/acanthus_client/Acanthus.java
+++ b/app/src/main/java/org/ntlab/acanthus_client/Acanthus.java
@@ -21,7 +21,7 @@
     private String preferenceToken;
     //-----------------------------------------------------------------
     private Integer aid;
-    private Integer editingPageNo;
+    private Integer editingPageNo = 0;
     private Animation currentAnimation;
     private Collection<AnimationJson> animationJsonList = new ArrayList<>();
 
@@ -76,6 +76,7 @@
     }
 
     public Integer getEditingPageNo() {
+        if (editingPageNo == null) editingPageNo = 0;
         return editingPageNo;
     }