diff --git a/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd b/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd
index 5237d23b0c0..ca76538a094 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd
+++ b/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd
@@ -1222,6 +1222,13 @@ Additional special types exist to flag options of special relevance to the build
                </appInfo>
             </annotation>
          </attribute>
+         <attribute name="contextId" type="string">
+            <annotation>
+               <documentation>
+                  specify a fully qualified context id for supplying context sensitive help for an option.
+               </documentation>
+            </annotation>
+         </attribute>
          <attribute name="valueHandler" type="string">
             <annotation>
                <documentation>