diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/PsiAntlrGrammarGenerator.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/PsiAntlrGrammarGenerator.xtend
index e3fcf34b5..759baa1de 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/PsiAntlrGrammarGenerator.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/PsiAntlrGrammarGenerator.xtend
@@ -33,9 +33,11 @@ class PsiAntlrGrammarGenerator extends AbstractAntlrGrammarWithActionsGenerator
 	
 	@Inject
 	extension IdeaPluginClassNames
+	@Inject
+	extension PsiGrammarNaming naming
 	
-	override protected getGrammarClass(Grammar it) {
-		getGrammarClass('Psi')
+	override protected getGrammarNaming() {
+		naming
 	}
 	
 	override protected compileOptions(Grammar it, AntlrOptions options) '''
diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/PsiGrammarNaming.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/PsiGrammarNaming.xtend
new file mode 100644
index 000000000..1278cb511
--- /dev/null
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/PsiGrammarNaming.xtend
@@ -0,0 +1,28 @@
+/*******************************************************************************
+ * Copyright (c) 2015 itemis AG (http://www.itemis.eu) and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *******************************************************************************/
+package org.eclipse.xtext.xtext.generator.idea.parser.antlr
+
+import com.google.inject.Inject
+import com.google.inject.Singleton
+import org.eclipse.xtext.Grammar
+import org.eclipse.xtext.xtext.generator.XtextGeneratorNaming
+import org.eclipse.xtext.xtext.generator.parser.antlr.GrammarNaming
+import org.eclipse.xtext.xtext.generator.model.TypeReference
+import static extension org.eclipse.xtext.GrammarUtil.*
+
+@Singleton
+class PsiGrammarNaming extends GrammarNaming {
+	@Inject
+	extension XtextGeneratorNaming
+	
+	override String getParserPackage(Grammar it) '''«ideaBasePackage».parser.antlr.internal'''
+
+	override getGrammarClass(Grammar it) {
+		new TypeReference(parserPackage, '''PsiInternal«simpleName»''')
+	}
+}
\ No newline at end of file
diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/XtextAntlrIDEAGeneratorFragment.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/XtextAntlrIDEAGeneratorFragment.xtend
index 27ba7ebbb..c5acd1d14 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/XtextAntlrIDEAGeneratorFragment.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/idea/parser/antlr/XtextAntlrIDEAGeneratorFragment.xtend
@@ -15,15 +15,17 @@ import org.eclipse.xtext.xtext.generator.parser.antlr.AbstractAntlrGeneratorFrag
 class XtextAntlrIDEAGeneratorFragment extends AbstractAntlrGeneratorFragment2 {
 
 	@Inject
-	extension PsiAntlrGrammarGenerator
+	PsiAntlrGrammarGenerator generator
 
 	@Inject CodeConfig codeConfig
 
 	@Inject IXtextProjectConfig projectConfig
+	
+	@Inject extension PsiGrammarNaming
 
 	override protected doGenerate() {
 		val fsa = projectConfig.ideaPluginSrcGen
-		grammar.generate(options, fsa)
+		generator.generate(grammar, options, fsa)
 
 		val encoding = codeConfig.encoding
 		val grammarFileName = '''«grammar.grammarClass.path».g'''
diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AbstractAntlrGrammarGenerator.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AbstractAntlrGrammarGenerator.xtend
index c7df100b5..f520c19f9 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AbstractAntlrGrammarGenerator.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AbstractAntlrGrammarGenerator.xtend
@@ -30,7 +30,6 @@ import org.eclipse.xtext.xtext.generator.CodeConfig
 import org.eclipse.xtext.xtext.generator.XtextGeneratorNaming
 import org.eclipse.xtext.xtext.generator.grammarAccess.GrammarAccessExtensions
 import org.eclipse.xtext.xtext.generator.model.IXtextGeneratorFileSystemAccess
-import org.eclipse.xtext.xtext.generator.model.TypeReference
 
 import static extension org.eclipse.xtext.GrammarUtil.*
 import static extension org.eclipse.xtext.xtext.generator.parser.antlr.AntlrGrammarGenUtil.*
@@ -44,9 +43,6 @@ abstract class AbstractAntlrGrammarGenerator {
 	@Inject
 	protected extension GrammarAccessExtensions
 	
-	@Inject
-	protected extension GrammarNaming
-	
 	@Inject CodeConfig codeConfig
 	
 	def generate(Grammar it, AntlrOptions options, IXtextGeneratorFileSystemAccess fsa) {
@@ -54,14 +50,14 @@ abstract class AbstractAntlrGrammarGenerator {
 		filter.discardUnreachableRules = options.skipUnusedRules
 		val RuleNames ruleNames = RuleNames.getRuleNames(grammar, true);
 		val Grammar flattened = new FlattenedGrammarAccess(ruleNames, filter).getFlattenedGrammar();
-		fsa.generateFile(grammarClass.path + '.g', flattened.compile(options))
+		fsa.generateFile(grammarNaming.getGrammarClass(it).path + '.g', flattened.compile(options))
 	}
 	
-	protected abstract def TypeReference getGrammarClass(Grammar it)
+	protected abstract def GrammarNaming getGrammarNaming()
 	
 	protected def compile(Grammar it, AntlrOptions options) '''
 		«codeConfig.fileHeader»
-		grammar «grammarClass.simpleName»;
+		grammar «grammarNaming.getGrammarClass(it).simpleName»;
 		«compileOptions(options)»
 		«compileTokens(options)»
 		«compileLexerHeader(options)»
@@ -82,7 +78,7 @@ abstract class AbstractAntlrGrammarGenerator {
 	protected def compileLexerHeader(Grammar it, AntlrOptions options) '''
 		
 		@lexer::header {
-		package «grammarClass.packageName»;
+		package «grammarNaming.getGrammarClass(it).packageName»;
 		«compileLexerImports(options)»
 		}
 	'''
@@ -97,7 +93,7 @@ abstract class AbstractAntlrGrammarGenerator {
 	protected def compileParserHeader(Grammar it, AntlrOptions options) '''
 		
 		@parser::header {
-		package «grammarClass.packageName»;
+		package «grammarNaming.getGrammarClass(it).packageName»;
 		«compileParserImports(options)»
 		}
 	'''
diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AntlrGrammarGenerator.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AntlrGrammarGenerator.xtend
index a8a4b42ad..d56ce3430 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AntlrGrammarGenerator.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/AntlrGrammarGenerator.xtend
@@ -27,12 +27,14 @@ import org.eclipse.xtext.xtext.generator.parser.antlr.AntlrOptions
 import static extension org.eclipse.xtext.EcoreUtil2.*
 import static extension org.eclipse.xtext.GrammarUtil.*
 import static extension org.eclipse.xtext.xtext.generator.parser.antlr.AntlrGrammarGenUtil.*
+import com.google.inject.Inject
 
 @Singleton
 class AntlrGrammarGenerator extends AbstractAntlrGrammarWithActionsGenerator {
+	@Inject extension GrammarNaming naming
 	
-	protected override getGrammarClass(Grammar it) {
-		getGrammarClass('')
+	protected override getGrammarNaming() {
+		naming
 	}
 	
 	protected override compileOptions(Grammar it, AntlrOptions options) '''
diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/GrammarNaming.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/GrammarNaming.xtend
index 337537b15..43c4509df 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/GrammarNaming.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/parser/antlr/GrammarNaming.xtend
@@ -21,10 +21,10 @@ class GrammarNaming {
 	@Inject
 	extension XtextGeneratorNaming
 
-	def String getParserPackage(Grammar it) '''«runtimeBasePackage».idea.parser.antlr.internal'''
+	def String getParserPackage(Grammar it) '''«runtimeBasePackage».parser.antlr.internal'''
 
-	def TypeReference getGrammarClass(Grammar it, String prefix) {
-		new TypeReference(parserPackage, '''«prefix»Internal«simpleName»''')
+	def TypeReference getGrammarClass(Grammar it) {
+		new TypeReference(parserPackage, '''Internal«simpleName»''')
 	}
 
 	def TypeReference getInternalParserClass(Grammar it) {