diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/dataprovider/ConfigurationDataProvider.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/dataprovider/ConfigurationDataProvider.java
index 3da6ce0b9ce..a29a99e9ff1 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/dataprovider/ConfigurationDataProvider.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/dataprovider/ConfigurationDataProvider.java
@@ -409,7 +409,8 @@ public class ConfigurationDataProvider extends CConfigurationDataProvider implem
 					String langId = type.getLanguageId(tool);
 					if(langId != null){
 						ILanguageDescriptor des = (ILanguageDescriptor)langMap.remove(langId);
-						adjustInputType(tool, type, des);
+						if(des != null)
+							adjustInputType(tool, type, des);
 						continue;
 					} else {
 						IContentType[] cTypes = type.getSourceContentTypes();