diff --git a/main/src/main/scala/sbt/Main.scala b/main/src/main/scala/sbt/Main.scala
index 07cfbec51..5b70bd83f 100644
--- a/main/src/main/scala/sbt/Main.scala
+++ b/main/src/main/scala/sbt/Main.scala
@@ -823,14 +823,15 @@ object BuiltinCommands {
 
     val sbtVersionOpt = sbtVersionSystemOpt.orElse(sbtVersionBuildOpt)
 
-    val app = state.configuration.provider
-    sbtVersionOpt.foreach(
-      version =>
-        if (version != app.id.version()) {
-          state.log.warn(s"""sbt version mismatch, using: ${app.id
-            .version()}, in build.properties: "$version".""")
-        }
-    )
+    sbtVersionOpt.foreach { version =>
+      val appVersion = state.configuration.provider.id.version()
+      if (version != appVersion) {
+        state.log.warn(
+          s"sbt version mismatch, using: $appVersion, " +
+            s"""in build.properties: "$version", use 'reboot' to use the new value.""".stripMargin
+        )
+      }
+    }
   }
 
   def doLoadProject(s0: State, action: LoadAction.Value): State = {
diff --git a/sbt/src/sbt-test/project/sbt-version-change/build.sbt b/sbt/src/sbt-test/project/sbt-version-change/build.sbt
index 6d9dc4e80..f0dbd39a1 100644
--- a/sbt/src/sbt-test/project/sbt-version-change/build.sbt
+++ b/sbt/src/sbt-test/project/sbt-version-change/build.sbt
@@ -3,6 +3,6 @@ TaskKey[Unit]("checkSbtVersionWarning") := {
 	val logging = state.globalLogging
 	val currVersion = state.configuration.provider.id.version()
 	val contents = IO.read(logging.backing.file)
-	assert(contents.contains(s"""sbt version mismatch, using: $currVersion, in build.properties: "1.1.1"."""))
+	assert(contents.contains(s"""sbt version mismatch, using: $currVersion, in build.properties: "1.1.1", use 'reboot' to use the new value."""))
 	()
-}
\ No newline at end of file
+}