diff --git a/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java b/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java
index 9fce0c3d..72465a5b 100644
--- a/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java
+++ b/backend/src/main/java/ddangkong/controller/room/RoomMemberCookieEncryptor.java
@@ -10,7 +10,7 @@ public class RoomMemberCookieEncryptor {
     private static final String DEFAULT_PATH = "/api/balances/rooms";
     private static final String NONE = "None";
     private static final String LAX = "Lax";
-    private static final String LOCALHOST = "localhost";
+    private static final String LOCALHOST = "http://localhost";
 
     private final EncryptionUtils encryptionUtils;
 
@@ -32,7 +32,7 @@ public ResponseCookie getEncodedCookie(Object value, String requestURI) {
     }
 
     private String getSameSiteOption(String uri) {
-        if (uri.equals(LOCALHOST)) {
+        if (uri.startsWith(LOCALHOST)) {
             return NONE;
         }
         return LAX;
diff --git a/backend/src/test/java/ddangkong/controller/room/RoomMemberCookieEncryptorTest.java b/backend/src/test/java/ddangkong/controller/room/RoomMemberCookieEncryptorTest.java
index db88078e..68d564fe 100644
--- a/backend/src/test/java/ddangkong/controller/room/RoomMemberCookieEncryptorTest.java
+++ b/backend/src/test/java/ddangkong/controller/room/RoomMemberCookieEncryptorTest.java
@@ -20,7 +20,7 @@ class 방_멤버_쿠키_암호화 {
         void 로컬_환경인_경우_SameSite는_None_이다() {
             // given
             String value = "ThisIsMySecretKe";
-            String uri = "localhost";
+            String uri = "http://localhost:3306/api";
            
             // when
             ResponseCookie encodedCookie = roomMemberCookieEncryptor.getEncodedCookie(value, uri);