diff --git a/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.test.ts b/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.test.ts
index bf5ea9d944738..4173849550afc 100644
--- a/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.test.ts
+++ b/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.test.ts
@@ -148,7 +148,7 @@ layer("BitbucketPullRequestApi.layer", (it) => {
       });
 
       expect(filterOfCall(0)).toBe(
-        '(title ~ "page" OR description ~ "page") AND updated_on <= 2026-07-02T00:00:00+00:00',
+        '(title ~ "page" OR description ~ "page") AND updated_on < 2026-07-02T00:00:00.001Z',
       );
     }),
   );
diff --git a/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.ts b/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.ts
index d5ad8491ac86b..28ea54263f45b 100644
--- a/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.ts
+++ b/packages/source-control-bitbucket/src/server/BitbucketPullRequestApi.ts
@@ -1,9 +1,11 @@
 import * as Cache from "effect/Cache";
 import * as Context from "effect/Context";
+import * as DateTime from "effect/DateTime";
 import * as Duration from "effect/Duration";
 import * as Effect from "effect/Effect";
 import * as Exit from "effect/Exit";
 import * as Layer from "effect/Layer";
+import * as Option from "effect/Option";
 import * as Result from "effect/Result";
 import * as Schema from "effect/Schema";
 import type {
@@ -326,6 +328,15 @@ function filterLiteral(value: string): string {
   return value.replaceAll("\\", "\\\\").replaceAll('"', '\\"');
 }
 
+// Bitbucket keeps microseconds; include the cursor's whole millisecond before excluding seen IDs.
+function updatedBeforeFilter(updatedBefore: string): string {
+  return Option.match(DateTime.make(updatedBefore), {
+    onNone: () => `updated_on <= ${updatedBefore}`,
+    onSome: (instant) =>
+      `updated_on < ${DateTime.formatIso(DateTime.add(instant, { milliseconds: 1 }))}`,
+  });
+}
+
 function mergeStrategy(method: PullRequestMergeMethod | undefined): string {
   switch (method) {
     case "squash":
@@ -544,12 +555,12 @@ export const make = Effect.gen(function* () {
     listPullRequests: (input) =>
       withRepository(input.repository, (path) => {
         const search = input.query?.trim() ?? "";
-        // Exclude already-sent IDs at the inclusive timestamp before applying the page limit.
+        // Exclude already-sent IDs in the boundary millisecond before applying the page limit.
         const predicates = [
           ...(search.length === 0 ? [] : [searchFilter(search)]),
           ...(input.author === undefined ? [] : [authorFilter(input.author)]),
           ...(input.draft === undefined ? [] : [`draft = ${input.draft}`]),
-          ...(input.cursor === undefined ? [] : [`updated_on <= ${input.cursor.updatedBefore}`]),
+          ...(input.cursor === undefined ? [] : [updatedBeforeFilter(input.cursor.updatedBefore)]),
           ...(input.cursor?.seenAt ?? []).map((number) => `id != ${number}`),
         ];
         return listPage({
diff --git a/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.listing.test.ts b/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.listing.test.ts
index f68e010ac00b6..bfb1447d02dbb 100644
--- a/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.listing.test.ts
+++ b/packages/source-control-bitbucket/src/server/BitbucketPullRequestProvider.listing.test.ts
@@ -8,14 +8,18 @@ import * as BitbucketPullRequestProvider from "./BitbucketPullRequestProvider.ts
 
 it.effect("pages through rows that share an update instant by excluding those already sent", () =>
   Effect.gen(function* () {
-    const boundary = "2026-10-12T00:00:00.000Z";
-    const older = "2026-10-11T00:00:00.000Z";
+    // Bitbucket stamps to the microsecond; 3 shares 1 and 2's millisecond but sorts after them.
+    const boundary = "2026-10-12T00:00:00.000500+00:00";
+    const sameMillisecond = "2026-10-12T00:00:00.000200+00:00";
+    const older = "2026-10-11T00:00:00.000000+00:00";
+    const micros = (stamp: string) =>
+      Date.parse(stamp) * 1000 + Number(/\.\d{3}(\d{3})/.exec(stamp)?.[1] ?? 0);
     const rows = [1, 2, 3, 4, 5].map((id) => ({
       id,
       title: `Pull request ${id}`,
       state: "OPEN",
       created_on: older,
-      updated_on: id <= 3 ? boundary : older,
+      updated_on: id <= 2 ? boundary : id === 3 ? sameMillisecond : older,
       source: { branch: { name: `feat/${id}` } },
       destination: { branch: { name: "main" } },
       links: { html: { href: `https://bitbucket.org/acme/web/pull-requests/${id}` } },
@@ -30,13 +34,16 @@ it.effect("pages through rows that share an update instant by excluding those al
                 const filter =
                   new URL(url, "https://api.bitbucket.org").searchParams.get("q") ?? "";
                 filters.push(filter);
-                const updatedBefore = /updated_on <= (\S+)/.exec(filter)?.[1];
+                const [, operator, bound] = /updated_on (<=?) (\S+)/.exec(filter) ?? [];
                 const excluded = new Set(
                   Array.from(filter.matchAll(/id != (\d+)/g), (match) => Number(match[1])),
                 );
                 const values = rows.filter(
                   (row) =>
-                    (updatedBefore === undefined || row.updated_on <= updatedBefore) &&
+                    (bound === undefined ||
+                      (operator === "<"
+                        ? micros(row.updated_on) < micros(bound)
+                        : micros(row.updated_on) <= micros(bound))) &&
                     !excluded.has(row.id),
                 );
                 return Effect.succeed({ body: JSON.stringify({ values }), truncated: false });
@@ -69,16 +76,25 @@ it.effect("pages through rows that share an update instant by excluding those al
     );
     assert.isTrue(first.truncated);
 
-    const second = yield* list({ updatedBefore: boundary, delivered: 2, seenAt: [1, 2] });
+    // The cursor carries the instant cut to the millisecond, as the app normalizes it.
+    const second = yield* list({
+      updatedBefore: "2026-10-12T00:00:00.000Z",
+      delivered: 2,
+      seenAt: [1, 2],
+    });
     assert.deepStrictEqual(
       second.items.map((item) => item.number),
       [3, 4],
     );
-    assert.include(filters.at(-1), `updated_on <= ${boundary}`);
+    assert.include(filters.at(-1), "updated_on < 2026-10-12T00:00:00.001Z");
     assert.include(filters.at(-1), "id != 1");
     assert.include(filters.at(-1), "id != 2");
 
-    const last = yield* list({ updatedBefore: older, delivered: 4, seenAt: [4] });
+    const last = yield* list({
+      updatedBefore: "2026-10-11T00:00:00.000Z",
+      delivered: 4,
+      seenAt: [4],
+    });
     assert.deepStrictEqual(
       last.items.map((item) => item.number),
       [5],