diff --git a/idea-project-model/src/main/scala/org/jetbrains/idea/Storage.scala b/idea-project-model/src/main/scala/org/jetbrains/idea/Storage.scala
index 4caaad4..899cff3 100644
--- a/idea-project-model/src/main/scala/org/jetbrains/idea/Storage.scala
+++ b/idea-project-model/src/main/scala/org/jetbrains/idea/Storage.scala
@@ -43,7 +43,7 @@ object Storage {
 
   private def toXml(jdk: Option[String], languageLevel: Option[JavaLanguageLevel]): Elem =
     <project version="4">
-      <component name="ProjectRootManager" version="2" languageLevel={text(languageLevel)} default="false" assert-keyword="true" jdk-15="true" project-jdk-name={text(jdk)} project-jdk-type="JavaSDK">
+      <component name="ProjectRootManager" version="2" languageLevel={text(languageLevel)} default={format(languageLevel.isEmpty)} project-jdk-name={text(jdk)} project-jdk-type="JavaSDK">
         <output url="file://$PROJECT_DIR$/classes" />
       </component>
     </project>
diff --git a/idea-project-model/src/test/scala/org/jetbrains/sbt/idea/StorageTest.scala b/idea-project-model/src/test/scala/org/jetbrains/sbt/idea/StorageTest.scala
index f902ab8..426c1a1 100644
--- a/idea-project-model/src/test/scala/org/jetbrains/sbt/idea/StorageTest.scala
+++ b/idea-project-model/src/test/scala/org/jetbrains/sbt/idea/StorageTest.scala
@@ -82,7 +82,7 @@ class StorageTest {
 
     ".idea/misc.xml" ->
       <project version="4">
-        <component name="ProjectRootManager" version="2" languageLevel="JDK_1_5" default="false" assert-keyword="true" jdk-15="true" project-jdk-name="1.6" project-jdk-type="JavaSDK">
+        <component name="ProjectRootManager" version="2" languageLevel="JDK_1_5" default="false" project-jdk-name="1.6" project-jdk-type="JavaSDK">
           <output url="file://$PROJECT_DIR$/classes" />
         </component>
       </project>,