diff --git a/src/test/java/roomescape/theme/web/ThemeControllerTest.kt b/src/test/java/roomescape/theme/web/ThemeControllerTest.kt
index af3ea616..46893438 100644
--- a/src/test/java/roomescape/theme/web/ThemeControllerTest.kt
+++ b/src/test/java/roomescape/theme/web/ThemeControllerTest.kt
@@ -201,12 +201,13 @@ class ThemeControllerTest(mockMvc: MockMvc) : RoomescapeApiTest() {
                 )
 
                 every {
-                    themeRepository.existsByName(request.name)
-                } returns false
-
-                every {
-                    themeRepository.save(any())
-                } returns theme
+                    themeService.save(request)
+                } returns ThemeResponse(
+                        id = theme.id!!,
+                        name = theme.name,
+                        description = theme.description,
+                        thumbnail = theme.thumbnail
+                )
 
                 Then("201 응답을 받는다.") {
                     runPostTest(
diff --git a/src/test/java/roomescape/util/RoomescapeApiTest.kt b/src/test/java/roomescape/util/RoomescapeApiTest.kt
index a26299a3..e8a0088d 100644
--- a/src/test/java/roomescape/util/RoomescapeApiTest.kt
+++ b/src/test/java/roomescape/util/RoomescapeApiTest.kt
@@ -1,7 +1,6 @@
 package roomescape.util
 
 import com.fasterxml.jackson.databind.ObjectMapper
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
 import com.ninjasquad.springmockk.MockkBean
 import com.ninjasquad.springmockk.SpykBean
 import io.kotest.core.spec.style.BehaviorSpec
@@ -15,6 +14,7 @@ import roomescape.auth.infrastructure.jwt.JwtHandler
 import roomescape.auth.web.support.AdminInterceptor
 import roomescape.auth.web.support.LoginInterceptor
 import roomescape.auth.web.support.MemberIdResolver
+import roomescape.common.config.JacksonConfig
 import roomescape.common.exception.ErrorType
 import roomescape.common.exception.RoomescapeException
 import roomescape.member.business.MemberService
@@ -42,7 +42,7 @@ abstract class RoomescapeApiTest : BehaviorSpec() {
     @MockkBean
     lateinit var jwtHandler: JwtHandler
 
-    val objectMapper: ObjectMapper = jacksonObjectMapper()
+    val objectMapper: ObjectMapper = JacksonConfig().objectMapper()
     val admin: MemberEntity = MemberFixture.admin()
     val user: MemberEntity = MemberFixture.user()
 
@@ -71,9 +71,7 @@ abstract class RoomescapeApiTest : BehaviorSpec() {
         }
     }.apply {
         log.takeIf { it }?.let { this.andDo { print() } }
-    }.andExpect {
-        assert
-    }
+    }.andExpect(assert)
 
     fun runDeleteTest(
             mockMvc: MockMvc,
@@ -84,9 +82,7 @@ abstract class RoomescapeApiTest : BehaviorSpec() {
         header(HttpHeaders.COOKIE, "accessToken=token")
     }.apply {
         log.takeIf { it }?.let { this.andDo { print() } }
-    }.andExpect {
-        assert
-    }
+    }.andExpect(assert)
 
     fun loginAsAdmin() {
         every {