diff --git a/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java b/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java
index b52cf605..164f94eb 100644
--- a/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java
+++ b/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java
@@ -33,7 +33,7 @@ public ResponseCookie getEncodedCookie(Object value, String origin) {
     }
 
     private String getSameSiteOption(String origin) {
-        if (origin.startsWith(LOCALHOST)) {
+        if (origin != null && origin.startsWith(LOCALHOST)) {
             return NONE;
         }
         return LAX;