diff --git a/src/ssn/verify/verifyPatchmanifest.ts b/src/ssn/verify/verifyPatchmanifest.ts
index 3bb7cf6..dab27b5 100644
--- a/src/ssn/verify/verifyPatchmanifest.ts
+++ b/src/ssn/verify/verifyPatchmanifest.ts
@@ -133,10 +133,13 @@ export default function verifyPatchmanifest(manifestFile: xmlJs.Element, product
       throw new Error('Expected To element.');
     }
     //TODO: check if From and To are valid relations
-    //<ExtraDataItem>
+    //<ExtraData>
     const ExtraData = ReleaseUpdatePath.elements[2];
-    if (ExtraData.type !== 'element' || ExtraData.name !== 'ExtraData' || ExtraData.attributes !== undefined || ExtraData.elements === undefined) {
-      throw new Error('Expected ExtraData element.');
+    if (ExtraData.type !== 'element' || ExtraData.name !== 'ExtraData') {
+      throw new Error(`Expected ExtraData element in patch ${From.elements[0].text}to${To.elements[0].text}.`);
+    }
+    if (ExtraData.attributes !== undefined || ExtraData.elements === undefined) {
+      throw new Error(`Expected ExtraData element with no attributes but some children in patch ${From.elements[0].text}to${To.elements[0].text}.`);
     }
     for (let j = 0, jl = ExtraData.elements.length; j < jl; j += 1) {
       //<ExtraDataItem>