diff --git a/xtext-gradle-plugin/src/integTest/java/org/xtext/gradle/test/WhenTheEclipsePluginIsApplied.xtend b/xtext-gradle-plugin/src/integTest/java/org/xtext/gradle/test/WhenTheEclipsePluginIsApplied.xtend
index 954ff4b..345cba5 100644
--- a/xtext-gradle-plugin/src/integTest/java/org/xtext/gradle/test/WhenTheEclipsePluginIsApplied.xtend
+++ b/xtext-gradle-plugin/src/integTest/java/org/xtext/gradle/test/WhenTheEclipsePluginIsApplied.xtend
@@ -55,7 +55,7 @@ class WhenTheEclipsePluginIsApplied extends AbstractIntegrationTest {
 		prefs.shouldContain('generateGeneratedAnnotation', false)
 		prefs.shouldContain('includeDateInGenerated', false)
 		prefs.shouldContain('useJavaCompilerCompliance', false)
-		prefs.shouldContain('targetJavaVersion', 'Java6')
+		prefs.shouldContain('targetJavaVersion', 'JAVA6')
 		prefs.shouldContain('outlet.DEFAULT_OUTPUT.userOutputPerSourceFolder', true)
 		prefs.shouldContain('outlet.DEFAULT_OUTPUT.installDslAsPrimarySource', false)
 		prefs.shouldContain('outlet.DEFAULT_OUTPUT.hideLocalSyntheticVariables', true)
diff --git a/xtext-gradle-plugin/src/main/java/org/xtext/gradle/tasks/XtextEclipseSettings.xtend b/xtext-gradle-plugin/src/main/java/org/xtext/gradle/tasks/XtextEclipseSettings.xtend
index 0e0e420..03de8f0 100644
--- a/xtext-gradle-plugin/src/main/java/org/xtext/gradle/tasks/XtextEclipseSettings.xtend
+++ b/xtext-gradle-plugin/src/main/java/org/xtext/gradle/tasks/XtextEclipseSettings.xtend
@@ -54,7 +54,7 @@ class XtextEclipseSettings extends DefaultTask {
 			if (generatedAnnotation.comment !== null) {
 				prefs.put("generatedAnnotationComment", generatedAnnotation.comment)
 			}
-			prefs.put("targetJavaVersion", "Java" + JavaVersion.toVersion(javaSourceLevel).majorVersion)
+			prefs.put("targetJavaVersion", "JAVA" + JavaVersion.toVersion(javaSourceLevel).majorVersion)
 			prefs.putBoolean("useJavaCompilerCompliance", false)
 			outlets.forEach [ outlet |
 				addOutletPreferences(prefs, language, outlet)