diff --git a/sbt/src/main/scala/Import.scala b/sbt/src/main/scala/Import.scala
index ce277f03b..4fb5c29df 100644
--- a/sbt/src/main/scala/Import.scala
+++ b/sbt/src/main/scala/Import.scala
@@ -8,7 +8,8 @@ trait Import {
   type URI = java.net.URI
   type URL = java.net.URL
 
-  implicit def Seq2Vector[T](s: Seq[T]): Vector[T] = s.toVector
+  @deprecated("Will be removed in sbt 2", "1.0.0-RC3")
+  def Seq2Vector[T](s: Seq[T]): Vector[T] = s.toVector
 
   // sbt
   val StdoutOutput = sbt.OutputStrategy.StdoutOutput