diff --git a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages.mwe2 b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages.mwe2
index cf68a8e2e..9275796de 100644
--- a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages.mwe2
+++ b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages.mwe2
@@ -80,14 +80,14 @@ Workflow {
 			uri = "classpath:/org/eclipse/xtext/XtextGrammarTestLanguage.xtext"
 			fragment = @TestLanguagesFragments {}
 		}
-		language = { 
-			uri = "classpath:/org/eclipse/xtext/lexer/BacktrackingLexerTestLanguage.xtext"
-			fragment = @TestLanguagesFragmentsEx {
-				backtrack = true
-				backtrackLexer = true
-				memoize = true
-			}
-		}
+//		language = { 
+//			uri = "classpath:/org/eclipse/xtext/lexer/BacktrackingLexerTestLanguage.xtext"
+//			fragment = @TestLanguagesFragmentsEx {
+//				backtrack = true
+//				backtrackLexer = true
+//				memoize = true
+//			}
+//		}
 		language = { 
 			uri = "classpath:/org/eclipse/xtext/lexer/IgnoreCaseLexerTestLanguage.xtext"
 			fragment = @TestLanguagesFragmentsEx {
diff --git a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2 b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2
index ffda922f4..76225bd0f 100644
--- a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2
+++ b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2
@@ -102,15 +102,15 @@ Workflow {
 //		language = TestLanguage {
 //			name = "org.eclipse.xtext.XtextGrammarTestLanguage"
 //		}
-//		language = TestLanguage {
-//			name = "org.eclipse.xtext.lexer.BacktrackingLexerTestLanguage"
-//			parserOptions = {
-//				backtrack = true
-//				backtrackLexer = true
-//				memoize = true
-//				classSplitting = true
-//			}
-//		}
+		language = TestLanguage {
+			name = "org.eclipse.xtext.lexer.BacktrackingLexerTestLanguage"
+			parserOptions = {
+				backtrack = true
+				backtrackLexer = true
+				memoize = true
+				classSplitting = true
+			}
+		}
 //		
 //		language = TestLanguage { 
 //			name = "org.eclipse.xtext.lexer.IgnoreCaseLexerTestLanguage"