diff --git a/src/domain/apple/interfaceBuilderGraph.test.ts b/src/domain/apple/interfaceBuilderGraph.test.ts
index fb1c0b9ad..bfa2c71de 100644
--- a/src/domain/apple/interfaceBuilderGraph.test.ts
+++ b/src/domain/apple/interfaceBuilderGraph.test.ts
@@ -552,3 +552,32 @@ it("names the archive once per evidence record", () => {
     evidence.filter(({ description }) => description.includes(relativePath)),
   ).toEqual([]);
 });
+
+it("states each object's class, label, and ID once", () => {
+  const { objects } = parseInterfaceBuilderRecords({
+    "com.apple.ibtool.document.objects": {
+      "7": {
+        customClass: "NSButton",
+        label: "Start",
+        objectID: "7",
+        nibValues: { NSContents: "Start" },
+      },
+      button: { class: "UIButton", title: "Build", objectID: "authored" },
+    },
+  });
+  expect(objects).toEqual([
+    expect.objectContaining({
+      id: "7",
+      class_name: "NSButton",
+      name: "Start",
+      attributes: { nibValues: { NSContents: "Start" } },
+    }),
+    expect.objectContaining({
+      id: "button",
+      class_name: "UIButton",
+      name: "Build",
+      // Values that differ from the canonical fields stay as authored.
+      attributes: { class: "UIButton", title: "Build", objectID: "authored" },
+    }),
+  ]);
+});
diff --git a/src/domain/apple/interfaceBuilderKeyedArchive.ts b/src/domain/apple/interfaceBuilderKeyedArchive.ts
index 51b446b52..c0b7f3507 100644
--- a/src/domain/apple/interfaceBuilderKeyedArchive.ts
+++ b/src/domain/apple/interfaceBuilderKeyedArchive.ts
@@ -71,13 +71,23 @@ export const parseInterfaceBuilderRecords = (
       attributes["name"],
       className,
     );
+    // class_name, name, and id already carry these values; repeating them in
+    // attributes doubled them on every graph node.
+    const carried = new Set<string>();
+    if (attributes["customClass"] === className) carried.add("customClass");
+    if (attributes["label"] === label) carried.add("label");
+    if (attributes["objectID"] === id) carried.add("objectID");
     objects.push(
       objectNode.parse({
         id,
         kind: classifyObject(className),
         class_name: className,
         name: label ?? id,
-        attributes: jsonSafeRecord(attributes),
+        attributes: jsonSafeRecord(
+          Object.fromEntries(
+            Object.entries(attributes).filter(([key]) => !carried.has(key)),
+          ),
+        ),
       }),
     );
   }