diff --git a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/Actor.kt b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/Actor.kt
index 5823b111..684c3474 100644
--- a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/Actor.kt
+++ b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/Actor.kt
@@ -154,9 +154,7 @@ class Actor(
         return id == other.id
     }
 
-    override fun hashCode(): Int {
-        return id.hashCode()
-    }
+    override fun hashCode(): Int = id.hashCode()
 
     override fun toString(): String {
         return "Actor(" +
diff --git a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorDescription.kt b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorDescription.kt
index 78ef02a6..55cb6dc7 100644
--- a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorDescription.kt
+++ b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorDescription.kt
@@ -28,9 +28,7 @@ class ActorDescription(description: String) {
         return description == other.description
     }
 
-    override fun hashCode(): Int {
-        return description.hashCode()
-    }
+    override fun hashCode(): Int = description.hashCode()
 
     companion object {
         const val LENGTH = 10000
diff --git a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorScreenName.kt b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorScreenName.kt
index 29e13f03..4c594d73 100644
--- a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorScreenName.kt
+++ b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/actor/ActorScreenName.kt
@@ -29,9 +29,7 @@ class ActorScreenName(screenName: String) {
         return screenName == other.screenName
     }
 
-    override fun hashCode(): Int {
-        return screenName.hashCode()
-    }
+    override fun hashCode(): Int = screenName.hashCode()
 
     companion object {
         const val LENGTH = 300
diff --git a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/timeline/Timeline.kt b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/timeline/Timeline.kt
index 73817d2e..ca513707 100644
--- a/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/timeline/Timeline.kt
+++ b/hideout-core/src/main/kotlin/dev/usbharu/hideout/core/domain/model/timeline/Timeline.kt
@@ -35,9 +35,7 @@ class Timeline(
         return id == other.id
     }
 
-    override fun hashCode(): Int {
-        return id.hashCode()
-    }
+    override fun hashCode(): Int = id.hashCode()
 
     companion object {
         fun create(