diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/buildmodel/BuildDescription.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/buildmodel/BuildDescription.java
index 4b228d2621f..ee2bd314dac 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/buildmodel/BuildDescription.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/buildmodel/BuildDescription.java
@@ -2179,8 +2179,10 @@ public class BuildDescription implements IBuildDescription {
 				var = new String();
 
 			Set<BuildIOType> set = fVarToAddlInSetMap.get(var);
-			for (BuildIOType t : set) {
-				t.addResource(rc);
+			if(set != null){
+				for (BuildIOType t : set) {
+					t.addResource(rc);
+				}
 			}
 		}
 	}