diff --git a/com.avaloq.tools.ddk.xtext.generator/src/com/avaloq/tools/ddk/xtext/generator/DefaultFragmentWithOverride.xtend b/com.avaloq.tools.ddk.xtext.generator/src/com/avaloq/tools/ddk/xtext/generator/DefaultFragmentWithOverride.xtend
index e8d887e258..89a6e71a4c 100644
--- a/com.avaloq.tools.ddk.xtext.generator/src/com/avaloq/tools/ddk/xtext/generator/DefaultFragmentWithOverride.xtend
+++ b/com.avaloq.tools.ddk.xtext.generator/src/com/avaloq/tools/ddk/xtext/generator/DefaultFragmentWithOverride.xtend
@@ -46,8 +46,8 @@ class DefaultFragmentWithOverride extends AbstractXtextGeneratorFragment {
   }
 
   override checkConfiguration(Issues issues) {
-    overrideFragment.checkConfiguration(issues)
-    defaultFragment.checkConfiguration(issues)
+    overrideFragment?.checkConfiguration(issues)
+    defaultFragment?.checkConfiguration(issues)
   }
 
 }