diff --git a/src/main/java/life/mosu/mosuserver/global/handler/OAuth2LoginFailureHandler.java b/src/main/java/life/mosu/mosuserver/global/handler/OAuth2LoginFailureHandler.java
index 2964bc52..f2c26ea3 100644
--- a/src/main/java/life/mosu/mosuserver/global/handler/OAuth2LoginFailureHandler.java
+++ b/src/main/java/life/mosu/mosuserver/global/handler/OAuth2LoginFailureHandler.java
@@ -1,29 +1,56 @@
 package life.mosu.mosuserver.global.handler;
 
+import com.fasterxml.jackson.databind.ObjectMapper;
 import jakarta.servlet.ServletException;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import java.io.IOException;
+import life.mosu.mosuserver.global.exception.ErrorResponse;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.security.core.AuthenticationException;
 import org.springframework.security.oauth2.core.OAuth2AuthenticationException;
 import org.springframework.security.oauth2.core.OAuth2Error;
-import org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler;
+import org.springframework.security.web.authentication.AuthenticationFailureHandler;
 import org.springframework.stereotype.Component;
 
 @Slf4j
 @Component
-public class OAuth2LoginFailureHandler extends SimpleUrlAuthenticationFailureHandler {
+@RequiredArgsConstructor
+public class OAuth2LoginFailureHandler implements
+        AuthenticationFailureHandler {
+
+    private final ObjectMapper objectMapper;
 
     @Override
     public void onAuthenticationFailure(HttpServletRequest request, HttpServletResponse response,
             AuthenticationException exception) throws IOException, ServletException {
-        if (exception instanceof OAuth2AuthenticationException) {
-            OAuth2Error error = ((OAuth2AuthenticationException) exception).getError();
-            log.info("OAuth2 Error " + error.getErrorCode());
-            log.info("OAuth2 Description " + error.getDescription());
-            log.info(error.toString());
+
+        String errorCode = "UNKNOWN_ERROR";
+        String errorMessage = "로그인에 실패했습니다. 관리자에게 문의하세요.";
+
+        if (exception instanceof OAuth2AuthenticationException oAuth2Ex) {
+            OAuth2Error error = oAuth2Ex.getError();
+            errorCode = error.getErrorCode();
+            errorMessage = error.getDescription() != null ? error.getDescription() : errorCode;
+
+            log.info("OAuth2 Error: {}, Description: {}", error.getErrorCode(),
+                    error.getDescription());
         }
-        super.onAuthenticationFailure(request, response, exception);
+
+        ErrorResponse errorResponse = ErrorResponse.builder()
+                .status(HttpStatus.UNAUTHORIZED.value())
+                .message("인증에 실패했습니다")
+                .errors(errorMessage)
+                .code(errorCode)
+                .build();
+
+        response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
+        response.setContentType("application/json;charset=UTF-8");
+        response.setContentType(MediaType.APPLICATION_JSON_VALUE);
+
+        objectMapper.writeValue(response.getWriter(), errorResponse);
     }
 }
diff --git a/src/main/java/life/mosu/mosuserver/global/util/CookieBuilderUtil.java b/src/main/java/life/mosu/mosuserver/global/util/CookieBuilderUtil.java
index 3949908e..7f5ea9aa 100644
--- a/src/main/java/life/mosu/mosuserver/global/util/CookieBuilderUtil.java
+++ b/src/main/java/life/mosu/mosuserver/global/util/CookieBuilderUtil.java
@@ -81,7 +81,7 @@ public static ResponseCookie createDevelopResponseCookie(String name, String val
      */
     public static Cookie createDevelopCookie(String name, String value, Long maxAge) {
         Cookie cookie = createBaseServletCookie(name, value, maxAge);
-        cookie.setSecure(false);
+        cookie.setSecure(true);
         cookie.setDomain(".mosuedu.com");
         return cookie;
     }