diff --git a/app/src/main/java/org/ntlab/radishforandroidstudio/cactusClient/models/Bullet.java b/app/src/main/java/org/ntlab/radishforandroidstudio/cactusClient/models/Bullet.java
index 48be4fe..7aab4ae 100644
--- a/app/src/main/java/org/ntlab/radishforandroidstudio/cactusClient/models/Bullet.java
+++ b/app/src/main/java/org/ntlab/radishforandroidstudio/cactusClient/models/Bullet.java
@@ -98,7 +98,7 @@
     @Override
     public void update(double interval) {
         // サーバに弾を作成
-        if (!isCreatedOnServer) {
+        if (!isCreatedOnServer && !instanceId.equals("") && !playerId.equals("")) {
             BulletCreateConnection con = new BulletCreateConnection(instanceId, playerId);
             // set parameter