diff --git a/packages/snapshot/src/client.ts b/packages/snapshot/src/client.ts
index b15bee07baea..32279959a0d8 100644
--- a/packages/snapshot/src/client.ts
+++ b/packages/snapshot/src/client.ts
@@ -50,6 +50,7 @@ export interface SnapshotClientOptions {
   isEqual?: (received: unknown, expected: unknown) => boolean
 }
 
+// TODO: probably we don't need much refactoring here yet. separate refactoring
 export class SnapshotClient {
   snapshotStateMap: Map<string, SnapshotState> = new Map()
 
diff --git a/packages/snapshot/src/port/state.ts b/packages/snapshot/src/port/state.ts
index 10dcb89469d7..4c975155dfb9 100644
--- a/packages/snapshot/src/port/state.ts
+++ b/packages/snapshot/src/port/state.ts
@@ -23,6 +23,7 @@ import { saveRawSnapshots } from './rawSnapshot'
 
 import {
   addExtraLineBreaks,
+  DefaultMap,
   getSnapshotData,
   keyToTestName,
   normalizeNewlines,
@@ -54,7 +55,7 @@ export default class SnapshotState {
   private _initialData: SnapshotData
   private _inlineSnapshots: Array<InlineSnapshot>
   private _inlineSnapshotStacks: Array<ParsedStack & { testId: string }>
-  private _testIdToKeys = new Map<string, string[]>()
+  private _testIdToKeys = new DefaultMap<string, string[]>(() => [])
   private _rawSnapshots: Array<RawSnapshot>
   private _uncheckedKeys: Set<string>
   private _snapshotFormat: PrettyFormatOptions
@@ -125,7 +126,7 @@ export default class SnapshotState {
     this._inlineSnapshots = this._inlineSnapshots.filter(s => s.testId !== testId)
     this._inlineSnapshotStacks = this._inlineSnapshotStacks.filter(s => s.testId !== testId)
 
-    for (const key of this._testIdToKeys.get(testId) ?? []) {
+    for (const key of this._testIdToKeys.get(testId)) {
       const name = keyToTestName(key)
       const counter = this._counters.get(name)
       if (typeof counter !== 'undefined') {
@@ -252,14 +253,14 @@ export default class SnapshotState {
     error,
     rawSnapshot,
   }: SnapshotMatchOptions): SnapshotReturnOptions {
+    // this also increments counter for inline snapshots. maybe we don't need to?
     this._counters.set(testName, (this._counters.get(testName) || 0) + 1)
     const count = Number(this._counters.get(testName))
 
     if (!key) {
       key = testNameToKey(testName, count)
     }
-    this._testIdToKeys.set(testId, (this._testIdToKeys.get(testId) ?? []))
-    this._testIdToKeys.get(testId)?.push(key)
+    this._testIdToKeys.get(testId).push(key)
 
     // Do not mark the snapshot as "checked" if the snapshot is inline and
     // there's an external snapshot. This way the external snapshot can be
diff --git a/packages/snapshot/src/port/utils.ts b/packages/snapshot/src/port/utils.ts
index d3435a493354..111d15cb15f1 100644
--- a/packages/snapshot/src/port/utils.ts
+++ b/packages/snapshot/src/port/utils.ts
@@ -265,3 +265,19 @@ export function deepMergeSnapshot(target: any, source: any): any {
   }
   return target
 }
+
+export class DefaultMap<K, V> extends Map<K, V> {
+  constructor(
+    private defaultFn: (key: K) => V,
+    entries?: Iterable<readonly [K, V]>,
+  ) {
+    super(entries)
+  }
+
+  override get(key: K): V {
+    if (!this.has(key)) {
+      this.set(key, this.defaultFn(key))
+    }
+    return super.get(key)!
+  }
+}