diff --git a/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.test.ts b/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.test.ts
index 70f0ce906fe4..5b4e8e91c436 100644
--- a/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.test.ts
+++ b/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.test.ts
@@ -1,8 +1,11 @@
 import { processOutput } from "@t3tools/source-control-testing/TestSourceControlHost";
 import { assert, it } from "@effect/vitest";
+import * as Effect from "effect/Effect";
+import * as Layer from "effect/Layer";
 import * as Option from "effect/Option";
 import { ChildProcessSpawner } from "effect/process";
 
+import * as AzureDevOpsCli from "./AzureDevOpsCli.ts";
 import * as AzureDevOpsSourceControlProvider from "./AzureDevOpsSourceControlProvider.ts";
 
 const { parseAuth } = AzureDevOpsSourceControlProvider.discovery;
@@ -25,3 +28,18 @@ it("reads the signed-in Azure account and says when az is signed out", () => {
   );
   assert.strictEqual(parseAuth(processOutput("\n")).status, "unknown");
 });
+
+it.effect(
+  "looks up a branch's pull requests a full page at a time, past forks' same-named branches",
+  () =>
+    Effect.gen(function* () {
+      const provider = yield* AzureDevOpsSourceControlProvider.make;
+      assert.deepStrictEqual(
+        provider.headBranchProbe?.({
+          headSelectors: ["octocat:feature", "feature"],
+          state: "open",
+        }),
+        { headSelectors: ["feature"], limit: 100 },
+      );
+    }).pipe(Effect.provide(Layer.mock(AzureDevOpsCli.AzureDevOpsCli)({}))),
+);
diff --git a/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.ts b/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.ts
index 64c1ada9bc13..c63fa639f2de 100644
--- a/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.ts
+++ b/packages/source-control-azure-devops/src/server/AzureDevOpsSourceControlProvider.ts
@@ -76,6 +76,11 @@ export const make = Effect.gen(function* () {
 
   return SourceControlProvider.SourceControlProvider.of({
     kind: SourceControlProviderKind.make("azure-devops"),
+    // Azure lists fork pull requests by source branch with no owner filter, so read a full page.
+    headBranchProbe: ({ headSelectors }) => ({
+      headSelectors: headSelectors.filter((selector) => !selector.includes(":")),
+      limit: 100,
+    }),
     listChangeRequests: Effect.fn("AzureDevOpsSourceControlProvider.listChangeRequests")(
       function (input) {
         const source = SourceControlProvider.sourceControlRefFromInput(input);