diff --git a/sbt b/sbt
index d51c19ee1..e5c821537 100755
--- a/sbt
+++ b/sbt
@@ -95,9 +95,9 @@ while [ $# -gt 0 ]; do
 
           -D*) addJava "$1"; shift ;;
           -J*) addJava "${1:2}"; shift ;;
-          -28) addSbt "set scalaVersion := \"$latest_28\""; shift ;;
-          -29) addSbt "set scalaVersion := \"$latest_29\""; shift ;;
-         -210) addSbt "set scalaVersion := \"$latest_210\""; shift ;;
+          -28) addSbt "set scalaVersion in ThisBuild := \"$latest_28\""; shift ;;
+          -29) addSbt "set scalaVersion in ThisBuild := \"$latest_29\""; shift ;;
+         -210) addSbt "set scalaVersion in ThisBuild := \"$latest_210\""; shift ;;
        -debug) addSbt "set logLevel in Global := Level.Debug"; debug=1; shift ;;
        -local) addSbt "set scalaHome in ThisBuild := Some(file(\"$2\"))"; shift 2 ;;