diff --git a/src/main/java/com/example/cosmos_serversb/models/Groups.java b/src/main/java/com/example/cosmos_serversb/models/Groups.java
index 757ada5..cc6756c 100644
--- a/src/main/java/com/example/cosmos_serversb/models/Groups.java
+++ b/src/main/java/com/example/cosmos_serversb/models/Groups.java
@@ -166,7 +166,7 @@
     }
 
     public static Request addRequests(String gId, String uId, String product, String deadline, int location){
-        if(product == null){
+        if(product == null || uId == null){
             return null; //not-null制約
         }
         String rId = getInstance().createRId();