diff --git a/packages/webhook-ingestion/src/github/payload.ts b/packages/webhook-ingestion/src/github/payload.ts
index abbd286..9f7e078 100644
--- a/packages/webhook-ingestion/src/github/payload.ts
+++ b/packages/webhook-ingestion/src/github/payload.ts
@@ -56,6 +56,21 @@ const optionalProviderId = (record: JsonRecord, key: string): string | undefined
 const withOptional = <K extends string, V>(key: K, value: V | undefined): Partial<Record<K, V>> =>
   value === undefined ? {} : ({ [key]: value } as Record<K, V>);
 
+/** Returns the account associated with a GitHub App installation webhook payload. */
+const installationAccount = (payload: JsonRecord): JsonRecord => {
+  const installation = asRecord(payload.installation, "installation");
+  const account =
+    optionalRecord(installation.account) ??
+    optionalRecord(optionalRecord(payload.repository)?.owner) ??
+    optionalRecord(payload.sender);
+
+  if (!account) {
+    throw new WebhookPayloadError("GitHub payload is missing installation.account.");
+  }
+
+  return account;
+};
+
 const numberValue = (record: JsonRecord, key: string): number => {
   const value = record[key];
   if (typeof value === "number") {
@@ -165,9 +180,8 @@ export type NormalizedGitHubFeedback = {
 
 /** Extracts a GitHub installation account. */
 export function normalizeGitHubAccount(payload: JsonRecord): NormalizedGitHubAccount {
-  const installation = asRecord(payload.installation, "installation");
-  const account = asRecord(installation.account, "installation.account");
-  const providerAccountId = stringValue(account, "id");
+  const account = installationAccount(payload);
+  const providerAccountId = optionalProviderId(account, "id") ?? stringValue(account, "login");
   const login = stringValue(account, "login");
   const rawType = optionalString(account, "type")?.toLowerCase();
   const accountType =
diff --git a/packages/webhook-ingestion/test/fixtures.ts b/packages/webhook-ingestion/test/fixtures.ts
index ba1d05c..51a459c 100644
--- a/packages/webhook-ingestion/test/fixtures.ts
+++ b/packages/webhook-ingestion/test/fixtures.ts
@@ -25,7 +25,9 @@ export const installationPayload = {
       default_branch: "main",
       clone_url: "https://github.com/acme/heimdall.git",
       owner: {
+        id: 42,
         login: "acme",
+        type: "Organization",
       },
     },
   ],
diff --git a/packages/webhook-ingestion/test/github-normalize.test.ts b/packages/webhook-ingestion/test/github-normalize.test.ts
index 0278201..fed10ed 100644
--- a/packages/webhook-ingestion/test/github-normalize.test.ts
+++ b/packages/webhook-ingestion/test/github-normalize.test.ts
@@ -34,6 +34,25 @@ describe("GitHub webhook normalization", () => {
     expect(pullRequest.snapshot.diffHash).toMatch(/^sha256:[a-f0-9]{64}$/u);
   });
 
+  it("normalizes pull request payloads when installation account is omitted", () => {
+    const payload = {
+      ...pullRequestPayload,
+      installation: {
+        id: pullRequestPayload.installation.id,
+      },
+    };
+
+    const installation = normalizeGitHubInstallation(payload);
+    const pullRequest = normalizeGitHubPullRequest(payload);
+
+    expect(installation).toMatchObject({
+      accountLogin: "acme",
+      accountType: "organization",
+      providerInstallationId: "123456",
+    });
+    expect(pullRequest.snapshot.pullRequestNumber).toBe(7);
+  });
+
   it("normalizes pull request comments and reactions as feedback", () => {
     const comment = normalizeGitHubFeedback(issueCommentPayload, "issue_comment");
     const reaction = normalizeGitHubFeedback(reactionPayload, "reaction");