diff --git a/core/src/main/scala/akka/persistence/r2dbc/internal/sqlserver/SqlServerQueryDao.scala b/core/src/main/scala/akka/persistence/r2dbc/internal/sqlserver/SqlServerQueryDao.scala
index 9ddbafd4..504e0bbc 100644
--- a/core/src/main/scala/akka/persistence/r2dbc/internal/sqlserver/SqlServerQueryDao.scala
+++ b/core/src/main/scala/akka/persistence/r2dbc/internal/sqlserver/SqlServerQueryDao.scala
@@ -5,9 +5,6 @@
 package akka.persistence.r2dbc.internal.sqlserver
 
 import java.time.Instant
-import java.time.LocalDateTime
-import java.time.ZoneId
-import java.util.Date.UTC
 
 import scala.concurrent.ExecutionContext
 import scala.concurrent.Future
@@ -19,7 +16,6 @@ import akka.annotation.InternalApi
 import akka.persistence.r2dbc.R2dbcSettings
 import akka.persistence.r2dbc.internal.InstantFactory
 import akka.persistence.r2dbc.internal.Sql.Interpolation
-import akka.persistence.r2dbc.internal.codec.TimestampCodec.SqlServerTimestampCodec
 import akka.persistence.r2dbc.internal.codec.TimestampCodec.TimestampCodecRichStatement
 import akka.persistence.r2dbc.internal.postgres.PostgresQueryDao
 import io.r2dbc.spi.ConnectionFactory
diff --git a/core/src/test/scala/akka/persistence/r2dbc/journal/PersistTagsSpec.scala b/core/src/test/scala/akka/persistence/r2dbc/journal/PersistTagsSpec.scala
index 914ee1c2..d48452a4 100644
--- a/core/src/test/scala/akka/persistence/r2dbc/journal/PersistTagsSpec.scala
+++ b/core/src/test/scala/akka/persistence/r2dbc/journal/PersistTagsSpec.scala
@@ -29,7 +29,7 @@ class PersistTagsSpec
 
   override def typedSystem: ActorSystem[_] = system
   private val settings = R2dbcSettings(system.settings.config.getConfig("akka.persistence.r2dbc"))
-  implicit val tagsCodec: TagsCodec = settings.tagsCodec
+  private implicit val tagsCodec: TagsCodec = settings.tagsCodec
   case class Row(pid: String, seqNr: Long, tags: Set[String])
 
   "Persist tags" should {
diff --git a/migration/src/main/scala/akka/persistence/r2dbc/migration/MigrationToolDao.scala b/migration/src/main/scala/akka/persistence/r2dbc/migration/MigrationToolDao.scala
index 4f804280..eca09b61 100644
--- a/migration/src/main/scala/akka/persistence/r2dbc/migration/MigrationToolDao.scala
+++ b/migration/src/main/scala/akka/persistence/r2dbc/migration/MigrationToolDao.scala
@@ -40,7 +40,7 @@ import org.slf4j.LoggerFactory
     logDbCallsExceeding: FiniteDuration,
     closeCallsExceeding: Option[FiniteDuration])(implicit ec: ExecutionContext, system: ActorSystem[_]) {
   import MigrationToolDao._
-  implicit val queryAdapter: QueryAdapter = IdentityAdapter
+  private implicit val queryAdapter: QueryAdapter = IdentityAdapter
   private val r2dbcExecutor =
     new R2dbcExecutor(connectionFactory, log, logDbCallsExceeding, closeCallsExceeding)(ec, system)