diff --git a/src/main/scala/sbt/Main.scala b/src/main/scala/sbt/Main.scala
index 913c2010e..907115a6c 100755
--- a/src/main/scala/sbt/Main.scala
+++ b/src/main/scala/sbt/Main.scala
@@ -101,7 +101,7 @@ class xMain extends xsbti.AppMain
 	private def startProject(project: Project, configuration: xsbti.AppConfiguration, remainingArguments: List[String], startTime: Long): xsbti.MainResult =
 	{
 		project.log.info("Building project " + project.name + " " + project.version.toString + " against Scala " + project.buildScalaVersion)
-		project.log.info("   using " + project.getClass.getName + " with sbt " + project.sbtVersion.value + " and Scala " + project.defScalaVersion.value)
+		project.log.info("   using " + project.getClass.getName + " with sbt " + ComponentManager.version + " and Scala " + project.defScalaVersion.value)
 		processArguments(project, initialize(remainingArguments), configuration, startTime) match
 		{
 			case e: xsbti.Exit =>
diff --git a/src/main/scala/sbt/Project.scala b/src/main/scala/sbt/Project.scala
index bfb1d284e..add3433e2 100644
--- a/src/main/scala/sbt/Project.scala
+++ b/src/main/scala/sbt/Project.scala
@@ -215,6 +215,9 @@ trait Project extends TaskManager with Dag[Project] with BasicEnvironment
 	* from the version of Scala used to build the project (current version used is buildScalaVersion, available are in buildScalaVersions).
 	* This property is only read by `sbt` on startup and reload.*/
 	final val defScalaVersion = propertyOptional[String](info.definitionScalaVersion)
+	/** The property to specify the sbt revision to use.
+	* Note that this can by a dynamic revision (see Ivy documentation for details on dynamic revisions).
+	*Therefore, use `sbt.ComponentManager.version` and `timestamp` for actual version information. */
 	final val sbtVersion = property[String]
 	final val projectInitialize = propertyOptional[Boolean](false)
 	final val projectScratch = propertyOptional[Boolean](false, true)
@@ -223,9 +226,10 @@ trait Project extends TaskManager with Dag[Project] with BasicEnvironment
 	* This property is only read by `sbt` on startup and reload.  The definitive source for the version of Scala currently
 	* being used is buildScalaVersion.*/
 	final val buildScalaVersions = propertyOptional[String](defScalaVersion.value, true)
-	/** The definitive source for the version of Scala being used to *build* the project.*/
+	/** The definitive source for the version of Scala being requested to *build* the project.
+	* For the full version information, see buildScalaInstance.actualVersion.*/
 	def buildScalaVersion = info.buildScalaVersion.getOrElse(crossScalaVersions.first)
-	private[sbt] def isScala27 = buildScalaVersion.startsWith("2.7.")
+	private[sbt] def isScala27 = buildScalaInstance.actualVersion.startsWith("2.7.")
 
 
 	def componentManager = new ComponentManager(info.launcher.globalLock, info.app.components, log)