diff --git a/packages/firestore/src/protos/firestore_proto_api.ts b/packages/firestore/src/protos/firestore_proto_api.ts
index 08ed4f676be..4e184f91071 100644
--- a/packages/firestore/src/protos/firestore_proto_api.ts
+++ b/packages/firestore/src/protos/firestore_proto_api.ts
@@ -456,6 +456,7 @@ export declare type BeginTransactionRequest =
   firestoreV1ApiClientInterfaces.BeginTransactionRequest;
 export declare type BeginTransactionResponse =
   firestoreV1ApiClientInterfaces.BeginTransactionResponse;
+export declare type BloomFilter = firestoreV1ApiClientInterfaces.BloomFilter;
 export declare type CollectionSelector =
   firestoreV1ApiClientInterfaces.CollectionSelector;
 export declare type CommitRequest =
diff --git a/packages/firestore/src/remote/existence_filter.ts b/packages/firestore/src/remote/existence_filter.ts
index ec2240851ed..377b1f017da 100644
--- a/packages/firestore/src/remote/existence_filter.ts
+++ b/packages/firestore/src/remote/existence_filter.ts
@@ -15,7 +15,8 @@
  * limitations under the License.
  */
 
+import { BloomFilter as ProtoBloomFilter } from '../protos/firestore_proto_api';
+
 export class ExistenceFilter {
-  // TODO(b/33078163): just use simplest form of existence filter for now
-  constructor(public count: number) {}
+  constructor(public count: number, public unchangedNames?: ProtoBloomFilter) {}
 }
diff --git a/packages/firestore/src/remote/serializer.ts b/packages/firestore/src/remote/serializer.ts
index c537648775f..bbf6a112642 100644
--- a/packages/firestore/src/remote/serializer.ts
+++ b/packages/firestore/src/remote/serializer.ts
@@ -537,8 +537,8 @@ export function fromWatchChange(
     assertPresent(change.filter, 'filter');
     const filter = change.filter;
     assertPresent(filter.targetId, 'filter.targetId');
-    const count = filter.count || 0;
-    const existenceFilter = new ExistenceFilter(count);
+    const { count = 0, unchangedNames } = filter;
+    const existenceFilter = new ExistenceFilter(count, unchangedNames);
     const targetId = filter.targetId;
     watchChange = new ExistenceFilterChange(targetId, existenceFilter);
   } else {
diff --git a/packages/firestore/test/unit/specs/existence_filter_spec.test.ts b/packages/firestore/test/unit/specs/existence_filter_spec.test.ts
index 4943d986bd2..32346c31af5 100644
--- a/packages/firestore/test/unit/specs/existence_filter_spec.test.ts
+++ b/packages/firestore/test/unit/specs/existence_filter_spec.test.ts
@@ -31,7 +31,23 @@ describeSpec('Existence Filters:', [], () => {
       .userListens(query1)
       .watchAcksFull(query1, 1000, doc1)
       .expectEvents(query1, { added: [doc1] })
-      .watchFilters([query1], doc1.key)
+      .watchFilters([query1], [doc1.key])
+      .watchSnapshots(2000);
+  });
+
+  // This test is only to make sure watchFilters can accept bloom filter.
+  // TODO:(mila) update the tests when bloom filter logic is implemented.
+  specTest('Existence filter with bloom filter match', [], () => {
+    const query1 = query('collection');
+    const doc1 = doc('collection/1', 1000, { v: 1 });
+    return spec()
+      .userListens(query1)
+      .watchAcksFull(query1, 1000, doc1)
+      .expectEvents(query1, { added: [doc1] })
+      .watchFilters([query1], [doc1.key], {
+        bits: { bitmap: 'a', padding: 1 },
+        hashCount: 1
+      })
       .watchSnapshots(2000);
   });
 
@@ -45,7 +61,7 @@ describeSpec('Existence Filters:', [], () => {
       .watchSnapshots(2000)
       .expectEvents(query1, {})
       .watchSends({ affects: [query1] }, doc1)
-      .watchFilters([query1], doc1.key)
+      .watchFilters([query1], [doc1.key])
       .watchSnapshots(2000)
       .expectEvents(query1, { added: [doc1] });
   });
@@ -59,7 +75,7 @@ describeSpec('Existence Filters:', [], () => {
       .watchCurrents(query1, 'resume-token-1000')
       .watchSnapshots(2000)
       .expectEvents(query1, {})
-      .watchFilters([query1], doc1.key)
+      .watchFilters([query1], [doc1.key])
       .watchSnapshots(2000)
       .expectEvents(query1, { fromCache: true });
   });
@@ -96,7 +112,37 @@ describeSpec('Existence Filters:', [], () => {
         .userListens(query1)
         .watchAcksFull(query1, 1000, doc1, doc2)
         .expectEvents(query1, { added: [doc1, doc2] })
-        .watchFilters([query1], doc1.key) // in the next sync doc2 was deleted
+        .watchFilters([query1], [doc1.key]) // in the next sync doc2 was deleted
+        .watchSnapshots(2000)
+        // query is now marked as "inconsistent" because of filter mismatch
+        .expectEvents(query1, { fromCache: true })
+        .expectActiveTargets({ query: query1, resumeToken: '' })
+        .watchRemoves(query1) // Acks removal of query
+        .watchAcksFull(query1, 2000, doc1)
+        .expectLimboDocs(doc2.key) // doc2 is now in limbo
+        .ackLimbo(2000, deletedDoc('collection/2', 2000))
+        .expectLimboDocs() // doc2 is no longer in limbo
+        .expectEvents(query1, {
+          removed: [doc2]
+        })
+    );
+  });
+
+  // This test is only to make sure watchFilters can accept bloom filter.
+  // TODO:(mila) update the tests when bloom filter logic is implemented.
+  specTest('Existence filter mismatch triggers bloom filter', [], () => {
+    const query1 = query('collection');
+    const doc1 = doc('collection/1', 1000, { v: 1 });
+    const doc2 = doc('collection/2', 1000, { v: 2 });
+    return (
+      spec()
+        .userListens(query1)
+        .watchAcksFull(query1, 1000, doc1, doc2)
+        .expectEvents(query1, { added: [doc1, doc2] })
+        .watchFilters([query1], [doc1.key], {
+          bits: { bitmap: 'a', padding: 1 },
+          hashCount: 3
+        }) // in the next sync doc2 was deleted
         .watchSnapshots(2000)
         // query is now marked as "inconsistent" because of filter mismatch
         .expectEvents(query1, { fromCache: true })
@@ -130,7 +176,7 @@ describeSpec('Existence Filters:', [], () => {
           resumeToken: 'existence-filter-resume-token'
         })
         .watchAcks(query1)
-        .watchFilters([query1], doc1.key) // in the next sync doc2 was deleted
+        .watchFilters([query1], [doc1.key]) // in the next sync doc2 was deleted
         .watchSnapshots(2000)
         // query is now marked as "inconsistent" because of filter mismatch
         .expectEvents(query1, { fromCache: true })
@@ -159,7 +205,7 @@ describeSpec('Existence Filters:', [], () => {
         // Send a mismatching existence filter with two documents, but don't
         // send a new global snapshot. We should not see an event until we
         // receive the snapshot.
-        .watchFilters([query1], doc1.key, doc2.key)
+        .watchFilters([query1], [doc1.key, doc2.key])
         .watchSends({ affects: [query1] }, doc3)
         .watchSnapshots(2000)
         // The query result includes doc3, but is marked as "inconsistent"
@@ -193,7 +239,7 @@ describeSpec('Existence Filters:', [], () => {
         .userListens(query1)
         .watchAcksFull(query1, 1000, doc1, doc2)
         .expectEvents(query1, { added: [doc1, doc2] })
-        .watchFilters([query1], doc1.key) // in the next sync doc2 was deleted
+        .watchFilters([query1], [doc1.key]) // in the next sync doc2 was deleted
         .watchSnapshots(2000)
         // query is now marked as "inconsistent" because of filter mismatch
         .expectEvents(query1, { fromCache: true })
@@ -229,7 +275,7 @@ describeSpec('Existence Filters:', [], () => {
           .userListens(query1)
           .watchAcksFull(query1, 1000, doc1, doc2)
           .expectEvents(query1, { added: [doc1, doc2] })
-          .watchFilters([query1], doc1.key) // doc2 was deleted
+          .watchFilters([query1], [doc1.key]) // doc2 was deleted
           .watchSnapshots(2000)
           .expectEvents(query1, { fromCache: true })
           // The SDK is unable to re-run the query, and does not remove doc2
diff --git a/packages/firestore/test/unit/specs/limbo_spec.test.ts b/packages/firestore/test/unit/specs/limbo_spec.test.ts
index b7db2049ec9..4451fc5a80a 100644
--- a/packages/firestore/test/unit/specs/limbo_spec.test.ts
+++ b/packages/firestore/test/unit/specs/limbo_spec.test.ts
@@ -880,7 +880,7 @@ describeSpec('Limbo Documents:', [], () => {
           // documents that changed since the resume token. This will cause it
           // to just send the docBs with an existence filter with a count of 3.
           .watchSends({ affects: [query1] }, docB1, docB2, docB3)
-          .watchFilters([query1], docB1.key, docB2.key, docB3.key)
+          .watchFilters([query1], [docB1.key, docB2.key, docB3.key])
           .watchSnapshots(1001)
           .expectEvents(query1, {
             added: [docB1, docB2, docB3],
diff --git a/packages/firestore/test/unit/specs/limit_spec.test.ts b/packages/firestore/test/unit/specs/limit_spec.test.ts
index 678f929743d..133fd1b1b22 100644
--- a/packages/firestore/test/unit/specs/limit_spec.test.ts
+++ b/packages/firestore/test/unit/specs/limit_spec.test.ts
@@ -341,7 +341,7 @@ describeSpec('Limits:', [], () => {
           // we receive an existence filter, which indicates that our view is
           // out of sync.
           .watchSends({ affects: [limitQuery] }, secondDocument)
-          .watchFilters([limitQuery], secondDocument.key)
+          .watchFilters([limitQuery], [secondDocument.key])
           .watchSnapshots(1004)
           .expectActiveTargets({ query: limitQuery, resumeToken: '' })
           .watchRemoves(limitQuery)
diff --git a/packages/firestore/test/unit/specs/spec_builder.ts b/packages/firestore/test/unit/specs/spec_builder.ts
index fe3f079edb4..a53015058db 100644
--- a/packages/firestore/test/unit/specs/spec_builder.ts
+++ b/packages/firestore/test/unit/specs/spec_builder.ts
@@ -33,6 +33,7 @@ import { DocumentKey } from '../../../src/model/document_key';
 import { FieldIndex } from '../../../src/model/field_index';
 import { JsonObject } from '../../../src/model/object_value';
 import { ResourcePath } from '../../../src/model/path';
+import { BloomFilter as ProtoBloomFilter } from '../../../src/protos/firestore_proto_api';
 import {
   isPermanentWriteError,
   mapCodeFromRpcCode,
@@ -769,7 +770,11 @@ export class SpecBuilder {
     return this;
   }
 
-  watchFilters(queries: Query[], ...docs: DocumentKey[]): this {
+  watchFilters(
+    queries: Query[],
+    docs: DocumentKey[] = [],
+    bloomFilter?: ProtoBloomFilter
+  ): this {
     this.nextStep();
     const targetIds = queries.map(query => {
       return this.getTargetId(query);
@@ -777,10 +782,7 @@ export class SpecBuilder {
     const keys = docs.map(key => {
       return key.path.canonicalString();
     });
-    const filter: SpecWatchFilter = [targetIds] as SpecWatchFilter;
-    for (const key of keys) {
-      filter.push(key);
-    }
+    const filter = { targetIds, keys, bloomFilter } as SpecWatchFilter;
     this.currentStep = {
       watchFilter: filter
     };
diff --git a/packages/firestore/test/unit/specs/spec_test_runner.ts b/packages/firestore/test/unit/specs/spec_test_runner.ts
index 8a6909b3f2e..f011856c860 100644
--- a/packages/firestore/test/unit/specs/spec_test_runner.ts
+++ b/packages/firestore/test/unit/specs/spec_test_runner.ts
@@ -693,13 +693,12 @@ abstract class TestRunner {
   }
 
   private doWatchFilter(watchFilter: SpecWatchFilter): Promise<void> {
-    const targetIds: TargetId[] = watchFilter[0];
+    const { targetIds, keys, bloomFilter } = watchFilter;
     debugAssert(
       targetIds.length === 1,
       'ExistenceFilters currently support exactly one target only.'
     );
-    const keys = watchFilter.slice(1);
-    const filter = new ExistenceFilter(keys.length);
+    const filter = new ExistenceFilter(keys.length, bloomFilter);
     const change = new ExistenceFilterChange(targetIds[0], filter);
     return this.doWatchEvent(change);
   }
@@ -1577,14 +1576,12 @@ export interface SpecClientState {
 }
 
 /**
- * [[<target-id>, ...], <key>, ...]
- * Note that the last parameter is really of type ...string (spread operator)
  * The filter is based of a list of keys to match in the existence filter
  */
-export interface SpecWatchFilter
-  extends Array<TargetId[] | string | undefined> {
-  '0': TargetId[];
-  '1': string | undefined;
+export interface SpecWatchFilter {
+  targetIds: TargetId[];
+  keys: string[];
+  bloomFilter?: api.BloomFilter;
 }
 
 export type SpecLimitType = 'LimitToFirst' | 'LimitToLast';
diff --git a/packages/firestore/test/util/helpers.ts b/packages/firestore/test/util/helpers.ts
index 24cb7bccf0d..2d6fbb69fc8 100644
--- a/packages/firestore/test/util/helpers.ts
+++ b/packages/firestore/test/util/helpers.ts
@@ -429,7 +429,8 @@ export function existenceFilterEvent(
   targetId: number,
   syncedKeys: DocumentKeySet,
   remoteCount: number,
-  snapshotVersion: number
+  snapshotVersion: number,
+  bloomFilter?: api.BloomFilter
 ): RemoteEvent {
   const aggregator = new WatchChangeAggregator({
     getRemoteKeysForTarget: () => syncedKeys,
@@ -437,7 +438,10 @@ export function existenceFilterEvent(
       targetData(targetId, TargetPurpose.Listen, 'foo')
   });
   aggregator.handleExistenceFilter(
-    new ExistenceFilterChange(targetId, new ExistenceFilter(remoteCount))
+    new ExistenceFilterChange(
+      targetId,
+      new ExistenceFilter(remoteCount, bloomFilter)
+    )
   );
   return aggregator.createRemoteEvent(version(snapshotVersion));
 }
diff --git a/packages/firestore/test/util/spec_test_helpers.ts b/packages/firestore/test/util/spec_test_helpers.ts
index c721d0e0675..66d4eae34c6 100644
--- a/packages/firestore/test/util/spec_test_helpers.ts
+++ b/packages/firestore/test/util/spec_test_helpers.ts
@@ -44,8 +44,9 @@ export function encodeWatchChange(
   if (watchChange instanceof ExistenceFilterChange) {
     return {
       filter: {
+        targetId: watchChange.targetId,
         count: watchChange.existenceFilter.count,
-        targetId: watchChange.targetId
+        unchangedNames: watchChange.existenceFilter.unchangedNames
       }
     };
   }