diff --git a/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalDAO.kt b/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalDAO.kt
index df0e3fa..d600f86 100644
--- a/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalDAO.kt
+++ b/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalDAO.kt
@@ -15,7 +15,7 @@ internal interface CharacterLocalDAO {
     fun favoriteList(): Flow<List<CharacterLocal>>
 
     @Insert(onConflict = OnConflictStrategy.REPLACE)
-    suspend fun favorite(item: CharacterLocal): Long
+    suspend fun favorite(item: CharacterLocal): Unit
 
     @Query("SELECT id FROM ${CharacterLocal.TABLE_NAME}")
     fun favoriteIds(): Flow<List<Long>>
diff --git a/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalRoomDataSource.kt b/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalRoomDataSource.kt
index ebe7b32..af7ce02 100644
--- a/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalRoomDataSource.kt
+++ b/data-room/src/main/kotlin/dev/thiagosouto/marvelpoc/data/room/CharacterLocalRoomDataSource.kt
@@ -10,15 +10,13 @@ import kotlinx.coroutines.flow.map
 internal class CharacterLocalRoomDataSource(private val characterDAO: CharacterLocalDAO) :
     CharacterLocalContract<Character> {
 
-    override suspend fun favorite(item: Character): Long =
+    override suspend fun favorite(item: Character): Unit =
         characterDAO.favorite(item.toCharacterLocal())
 
     override fun favoriteIds(): Flow<List<Long>> = characterDAO.favoriteIds()
 
-    override suspend fun unFavorite(item: Character): Long {
+    override suspend fun unFavorite(item: Character) =
         characterDAO.unFavorite(item.toCharacterLocal())
-        return item.id
-    }
 
     override fun favoritesList(): Flow<List<Character>> =
         characterDAO.favoriteList().map(::characterAdapter)
diff --git a/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/character/CharacterLocalContract.kt b/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/character/CharacterLocalContract.kt
index f61b3db..475f5b3 100644
--- a/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/character/CharacterLocalContract.kt
+++ b/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/character/CharacterLocalContract.kt
@@ -16,7 +16,7 @@ interface CharacterLocalContract<T : Any> {
     /**
      * favorite character and returns its id
      */
-    suspend fun favorite(item: T): Long
+    suspend fun favorite(item: T): Unit
 
     /**
      * return a list of favorite ids
@@ -26,5 +26,5 @@ interface CharacterLocalContract<T : Any> {
     /**
      * unfavorite character and returns its id
      */
-    suspend fun unFavorite(item: T): Long
+    suspend fun unFavorite(item: T): Unit
 }
diff --git a/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesService.kt b/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesService.kt
index 7c1ae57..ac4f7bf 100644
--- a/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesService.kt
+++ b/data/src/commonMain/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesService.kt
@@ -24,7 +24,7 @@ internal class DefaultFavoritesService(
      */
     override suspend fun unFavorite(
         item: Character
-    ) {
+    ) : Unit  {
         localDataSource.unFavorite(item)
     }
 
diff --git a/data/src/commonTest/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesServiceTest.kt b/data/src/commonTest/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesServiceTest.kt
index 9c47d18..01c63e1 100644
--- a/data/src/commonTest/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesServiceTest.kt
+++ b/data/src/commonTest/kotlin/dev/thiagosouto/marvelpoc/data/services/DefaultFavoritesServiceTest.kt
@@ -69,14 +69,12 @@ internal class DefaultFavoritesServiceTest {
 
         override fun favoriteIds(): Flow<List<Long>> = flowOf(characters.map { it.id })
 
-        override suspend fun unFavorite(item: Character): Long {
+        override suspend fun unFavorite(item: Character): Unit {
             characters.remove(item)
-            return item.id
         }
 
-        override suspend fun favorite(item: Character): Long {
+        override suspend fun favorite(item: Character): Unit {
             characters.add(item)
-            return item.id
         }
     }
 }