diff --git a/packages/@aws-cdk/cfnspec/build-tools/spec-diff.ts b/packages/@aws-cdk/cfnspec/build-tools/spec-diff.ts
index f4aa0ee7daab3..6b5a0d6d466f9 100644
--- a/packages/@aws-cdk/cfnspec/build-tools/spec-diff.ts
+++ b/packages/@aws-cdk/cfnspec/build-tools/spec-diff.ts
@@ -106,6 +106,11 @@ async function main() {
             });
           }
           break;
+        case 'Documentation':
+          describeChanges(resourceType, key, update.Documentation).forEach(change => {
+            attributeChanges.push(change);
+          });
+          break;
         default:
           throw new Error(`Unexpected update to ${resourceType}: ${key}`);
       }