diff --git a/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubUserServiceImpl.kt b/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubUserServiceImpl.kt
index 6c05fddf..5df6cb1c 100644
--- a/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubUserServiceImpl.kt
+++ b/src/main/kotlin/dev/usbharu/hideout/service/activitypub/ActivityPubUserServiceImpl.kt
@@ -93,7 +93,7 @@ class ActivityPubUserServiceImpl(
                 RemoteUserCreateDto(
                     name = person.preferredUsername
                         ?: throw IllegalActivityPubObjectException("preferredUsername is null"),
-                    domain = url.substringAfter("://").substringBeforeLast("/"),
+                    domain = url.substringAfter("://").substringBefore("/"),
                     screenName = (person.name ?: person.preferredUsername)
                         ?: throw IllegalActivityPubObjectException("preferredUsername is null"),
                     description = person.summary.orEmpty(),