diff --git a/gradle.properties b/gradle.properties
index 22f9b087..6ec87bb6 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -6,7 +6,7 @@ ksp.useKSP2=true
 group=org.komapper
 version=0.0.1
 
-ktorVersion=2.3.12
+ktorVersion=3.0.1
 kotlinVersion=2.0.21
 komapperVersion=4.0.0
 kspVersion=1.0.28
diff --git a/kweet/src/KweetApplication.kt b/kweet/src/KweetApplication.kt
index 558ed54a..2ba73f69 100644
--- a/kweet/src/KweetApplication.kt
+++ b/kweet/src/KweetApplication.kt
@@ -11,7 +11,7 @@ import io.ktor.server.application.Application
 import io.ktor.server.application.ApplicationCall
 import io.ktor.server.application.install
 import io.ktor.server.freemarker.FreeMarker
-import io.ktor.server.plugins.callloging.CallLogging
+import io.ktor.server.plugins.calllogging.CallLogging
 import io.ktor.server.plugins.conditionalheaders.ConditionalHeaders
 import io.ktor.server.plugins.defaultheaders.DefaultHeaders
 import io.ktor.server.plugins.partialcontent.PartialContent
@@ -78,6 +78,7 @@ class Logout()
 /**
  * Represents a session in this site containing the userId.
  */
+@Serializable
 data class KweetSession(val userId: String)
 
 /**
diff --git a/kweet/src/Register.kt b/kweet/src/Register.kt
index d4983a6a..ceda2b3e 100644
--- a/kweet/src/Register.kt
+++ b/kweet/src/Register.kt
@@ -3,8 +3,6 @@ package io.ktor.samples.kweet
 import io.ktor.http.Parameters
 import io.ktor.samples.kweet.dao.DAOFacade
 import io.ktor.samples.kweet.model.User
-import io.ktor.server.application.application
-import io.ktor.server.application.call
 import io.ktor.server.application.log
 import io.ktor.server.freemarker.FreeMarkerContent
 import io.ktor.server.request.receive
@@ -12,6 +10,7 @@ import io.ktor.server.resources.get
 import io.ktor.server.resources.post
 import io.ktor.server.response.respond
 import io.ktor.server.routing.Route
+import io.ktor.server.routing.application
 import io.ktor.server.sessions.get
 import io.ktor.server.sessions.sessions
 import io.ktor.server.sessions.set