diff --git a/src/domain/javascript/javascriptApplicationChangeGraph.ts b/src/domain/javascript/javascriptApplicationChangeGraph.ts
index ce0e136b3..4c80b3204 100644
--- a/src/domain/javascript/javascriptApplicationChangeGraph.ts
+++ b/src/domain/javascript/javascriptApplicationChangeGraph.ts
@@ -1,6 +1,6 @@
 import {
   createJavaScriptApplicationEdge,
-  createJavaScriptApplicationGraph,
+  createImmutableJavaScriptApplicationGraphSteps,
   createJavaScriptApplicationNode,
   type JavaScriptApplicationGraph,
 } from "./javascriptApplicationGraph.js";
@@ -59,7 +59,7 @@ export const buildJavaScriptApplicationChangeGraph = (
   const candidateEdges = uniqueEdges([...sourceEdges, ...comparisonEdges]);
   const rootNodeIds = preferredRoots.filter((nodeId) => retained.has(nodeId));
   const fallbackRoot = mergedNodes[0]?.node_id;
-  const graph = createJavaScriptApplicationGraph({
+  const steps = createImmutableJavaScriptApplicationGraphSteps({
     schema: "JavaScriptApplicationGraph",
     root_node_ids:
       rootNodeIds.length > 0
@@ -77,7 +77,9 @@ export const buildJavaScriptApplicationChangeGraph = (
       "The change graph contains compared entities and their retained relationships; it is not an executable application.",
     ]),
   });
-  return { graph };
+  let next = steps.next();
+  while (!next.done) next = steps.next();
+  return { graph: next.value };
 };
 
 const nodeCandidates = (
diff --git a/src/domain/javascript/javascriptApplicationVersionComparison.test.ts b/src/domain/javascript/javascriptApplicationVersionComparison.test.ts
new file mode 100644
index 000000000..c0d92cc38
--- /dev/null
+++ b/src/domain/javascript/javascriptApplicationVersionComparison.test.ts
@@ -0,0 +1,140 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  createJavaScriptApplicationEdge,
+  createJavaScriptApplicationGraph,
+  createJavaScriptApplicationNode,
+  isValidatedImmutableJavaScriptApplicationGraph,
+  parseJavaScriptApplicationGraph,
+  type JavaScriptApplicationGraph,
+} from "./javascriptApplicationGraph.js";
+import {
+  artifactEvidence,
+  completeCoverage,
+} from "./javascriptApplicationGraph.fixture.js";
+import { compareJavaScriptApplicationVersions } from "./javascriptApplicationVersionComparison.js";
+import {
+  applicationVersionComparisonResultSchema,
+  ownedApplicationVersionComparisonResultSchema,
+} from "./javascriptApplicationVersionComparisonSchemas.js";
+
+const LEFT_SHA = "a".repeat(64);
+const RIGHT_SHA = "b".repeat(64);
+
+const buildGraph = (
+  artifactSha: string,
+  version: number,
+): JavaScriptApplicationGraph => {
+  const nodes = ["a", "b", "c"].map((name) =>
+    createJavaScriptApplicationNode({
+      kind: "javascript-module",
+      identity: {
+        strategy: "canonical-path",
+        stability: "artifact-version",
+        artifact_sha256: artifactSha,
+        path: `${name}.js`,
+      },
+      observations: [
+        {
+          label: `${name}.js`,
+          properties: {
+            structural_fingerprint_sha256: name
+              .charCodeAt(0)
+              .toString(16)
+              .padStart(64, "0"),
+            structural_fingerprint_algorithm: "fixture",
+            source_sha256: (name === "b" ? version : 0)
+              .toString(16)
+              .padStart(64, "0"),
+          },
+          evidence: artifactEvidence(artifactSha, `${name}.js`),
+        },
+      ],
+    }),
+  );
+  const [a, b, c] = nodes;
+  if (a === undefined || b === undefined || c === undefined)
+    throw new Error("Missing fixture node");
+  return createJavaScriptApplicationGraph({
+    schema: "JavaScriptApplicationGraph",
+    root_node_ids: [a.node_id],
+    nodes,
+    edges: [
+      createJavaScriptApplicationEdge({
+        source_node_id: a.node_id,
+        target_node_id: b.node_id,
+        relation: "imports",
+        properties: {},
+        evidence: artifactEvidence(artifactSha, "a.js"),
+      }),
+      createJavaScriptApplicationEdge({
+        source_node_id: b.node_id,
+        target_node_id: c.node_id,
+        relation: "imports",
+        properties: {},
+        evidence: artifactEvidence(artifactSha, "b.js"),
+      }),
+    ],
+    coverage: completeCoverage,
+    limitations: [],
+  });
+};
+
+const compare = () =>
+  compareJavaScriptApplicationVersions({
+    left: {
+      evidenceId: `ev_${"1".repeat(64)}`,
+      rootArtifactSha256: LEFT_SHA,
+      graph: buildGraph(LEFT_SHA, 1),
+    },
+    right: {
+      evidenceId: `ev_${"2".repeat(64)}`,
+      rootArtifactSha256: RIGHT_SHA,
+      graph: buildGraph(RIGHT_SHA, 2),
+    },
+    leftNativeEvidence: [],
+    rightNativeEvidence: [],
+  });
+
+describe("application version comparison result", () => {
+  it("returns a sealed change graph that passes complete validation", () => {
+    const result = compare();
+    expect(
+      result.graph.edges.some(({ relation }) => relation === "changed_from"),
+    ).toBe(true);
+    expect(isValidatedImmutableJavaScriptApplicationGraph(result.graph)).toBe(
+      true,
+    );
+    expect(Object.isFrozen(result.graph.edges)).toBe(true);
+    expect(parseJavaScriptApplicationGraph(result.graph)).toEqual(result.graph);
+    expect(applicationVersionComparisonResultSchema.parse(result)).toEqual(
+      result,
+    );
+  });
+
+  it("does not reuse a change graph without an owned proof", () => {
+    const result = compare();
+    const copy = structuredClone(result.graph);
+    expect(isValidatedImmutableJavaScriptApplicationGraph(copy)).toBe(false);
+    expect(() =>
+      ownedApplicationVersionComparisonResultSchema.parse({
+        ...result,
+        graph: copy,
+      }),
+    ).toThrow();
+    expect(
+      applicationVersionComparisonResultSchema.parse({ ...result, graph: copy })
+        .graph,
+    ).toEqual(result.graph);
+  });
+
+  it("keeps coverage validation for owned results", () => {
+    const result = compare();
+    expect(() =>
+      ownedApplicationVersionComparisonResultSchema.parse({
+        ...result,
+        coverage: { ...result.coverage, status: "partial" },
+      }),
+    ).toThrow("Comparison coverage must match source graph completeness");
+  });
+});
diff --git a/src/domain/javascript/javascriptApplicationVersionComparison.ts b/src/domain/javascript/javascriptApplicationVersionComparison.ts
index 50f82c335..be60d067a 100644
--- a/src/domain/javascript/javascriptApplicationVersionComparison.ts
+++ b/src/domain/javascript/javascriptApplicationVersionComparison.ts
@@ -3,7 +3,7 @@ import { uniqueSorted } from "../canonicalOrdering.js";
 import type { Evidence } from "../evidence.js";
 import { buildJavaScriptApplicationChangeGraph } from "./javascriptApplicationChangeGraph.js";
 import {
-  applicationVersionComparisonResultSchema,
+  ownedApplicationVersionComparisonResultSchema,
   type ApplicationVersionComparisonResult,
 } from "./javascriptApplicationVersionComparisonSchemas.js";
 import type { JavaScriptApplicationGraph } from "./javascriptApplicationGraph.js";
@@ -76,7 +76,7 @@ export const compareJavaScriptApplicationVersions = (
     evidence_links: evidenceLinks,
     limitations: comparisonLimitations(input),
   };
-  return applicationVersionComparisonResultSchema.parse({
+  return ownedApplicationVersionComparisonResultSchema.parse({
     ...semantic,
     comparison_id: `javc_${digestCanonicalValue(semantic, "Application version comparison")}`,
   });
diff --git a/src/domain/javascript/javascriptApplicationVersionComparisonSchemas.ts b/src/domain/javascript/javascriptApplicationVersionComparisonSchemas.ts
index 309c95c89..d9d54449e 100644
--- a/src/domain/javascript/javascriptApplicationVersionComparisonSchemas.ts
+++ b/src/domain/javascript/javascriptApplicationVersionComparisonSchemas.ts
@@ -2,7 +2,11 @@ import { z } from "zod";
 
 import { emptyArraySchema } from "../emptyArraySchema.js";
 import { evidenceSchema } from "../evidence.js";
-import { javascriptApplicationGraphSchema } from "./javascriptApplicationGraph.js";
+import {
+  isValidatedImmutableJavaScriptApplicationGraph,
+  javascriptApplicationGraphSchema,
+  type JavaScriptApplicationGraph,
+} from "./javascriptApplicationGraph.js";
 import { JAVASCRIPT_APPLICATION_NODE_KINDS } from "./javascriptApplicationGraphSchemas.js";
 import { prefixedDigestSchema } from "../digests.js";
 
@@ -234,6 +238,14 @@ export const applicationVersionComparisonResultSchema = z
       });
   });
 
+/** Reuse the exact owned change graph while validating the rest of the result. */
+export const ownedApplicationVersionComparisonResultSchema =
+  applicationVersionComparisonResultSchema.safeExtend({
+    graph: z.custom<JavaScriptApplicationGraph>(
+      isValidatedImmutableJavaScriptApplicationGraph,
+    ),
+  });
+
 export type ApplicationVersionComparisonItem = z.infer<
   typeof comparisonItemSchema
 >;