diff --git a/main-command/src/main/scala/sbt/BasicKeys.scala b/main-command/src/main/scala/sbt/BasicKeys.scala
index f01b1f6a4..7d6693e19 100644
--- a/main-command/src/main/scala/sbt/BasicKeys.scala
+++ b/main-command/src/main/scala/sbt/BasicKeys.scala
@@ -93,7 +93,7 @@ object BasicKeys {
 
   val serverIdleTimeout =
     AttributeKey[Option[FiniteDuration]](
-      "serverIdleTimeOut",
+      "serverIdleTimeout",
       "If set to a defined value, sbt server will exit if it goes at least the specified duration without receiving any commands.",
       10000
     )