diff --git a/lib/create-contentful-api.ts b/lib/create-contentful-api.ts
index b616ee26a..345259205 100644
--- a/lib/create-contentful-api.ts
+++ b/lib/create-contentful-api.ts
@@ -5,7 +5,7 @@
 
 import { encodeCPAResponse } from '@contentful/content-source-maps'
 import { AxiosInstance, createRequestConfig, errorHandler } from 'contentful-sdk-core'
-import { CreateClientParams } from './contentful'
+import { CreateClientParams } from './contentful.js'
 import { GetGlobalOptions } from './create-global-options.js'
 import pagedSync from './paged-sync.js'
 import type {
@@ -28,7 +28,7 @@ import type {
 import normalizeSearchParameters from './utils/normalize-search-parameters.js'
 import normalizeSelect from './utils/normalize-select.js'
 import resolveCircular from './utils/resolve-circular.js'
-import getQuerySelectionSet from './utils/query-selection-set'
+import getQuerySelectionSet from './utils/query-selection-set.js'
 import validateTimestamp from './utils/validate-timestamp.js'
 import { ChainOptions, ModifiersFromOptions } from './utils/client-helpers.js'
 import {
@@ -36,8 +36,8 @@ import {
   validateLocaleParam,
   validateRemoveUnresolvedParam,
   validateResolveLinksParam,
-} from './utils/validate-params'
-import validateSearchParameters from './utils/validate-search-parameters'
+} from './utils/validate-params.js'
+import validateSearchParameters from './utils/validate-search-parameters.js'
 
 const ASSET_KEY_MAX_LIFETIME = 48 * 60 * 60
 
diff --git a/lib/types/asset.ts b/lib/types/asset.ts
index 136c44bac..c96a882e5 100644
--- a/lib/types/asset.ts
+++ b/lib/types/asset.ts
@@ -1,8 +1,8 @@
-import { ContentfulCollection } from './collection'
-import { LocaleCode } from './locale'
-import { Metadata } from './metadata'
-import { EntitySys } from './sys'
-import { ChainModifiers } from './client'
+import { ContentfulCollection } from './collection.js'
+import { LocaleCode } from './locale.js'
+import { Metadata } from './metadata.js'
+import { EntitySys } from './sys.js'
+import { ChainModifiers } from './client.js'
 
 /**
  * @category Asset
diff --git a/lib/types/client.ts b/lib/types/client.ts
index 34be7f63c..14192d2cd 100644
--- a/lib/types/client.ts
+++ b/lib/types/client.ts
@@ -1,6 +1,6 @@
-import { ContentType, ContentTypeCollection } from './content-type'
-import { Space } from './space'
-import { LocaleCode, LocaleCollection } from './locale'
+import { ContentType, ContentTypeCollection } from './content-type.js'
+import { Space } from './space.js'
+import { LocaleCode, LocaleCollection } from './locale.js'
 import {
   AssetQueries,
   AssetsQueries,
@@ -8,12 +8,12 @@ import {
   EntryQueries,
   EntrySkeletonType,
   TagQueries,
-} from './query'
-import { SyncCollection, SyncOptions, SyncQuery } from './sync'
-import { Tag, TagCollection } from './tag'
-import { AssetKey } from './asset-key'
-import { Entry, EntryCollection } from './entry'
-import { Asset, AssetCollection, AssetFields } from './asset'
+} from './query/index.js'
+import { SyncCollection, SyncOptions, SyncQuery } from './sync.js'
+import { Tag, TagCollection } from './tag.js'
+import { AssetKey } from './asset-key.js'
+import { Entry, EntryCollection } from './entry.js'
+import { Asset, AssetCollection, AssetFields } from './asset.js'
 
 /**
  * Client chain modifiers used in all types that depend on the client configuration.
diff --git a/lib/types/collection.ts b/lib/types/collection.ts
index dd412fde5..588a56be8 100644
--- a/lib/types/collection.ts
+++ b/lib/types/collection.ts
@@ -1,5 +1,5 @@
-import { AssetSys } from './asset'
-import { EntrySys } from './entry'
+import { AssetSys } from './asset.js'
+import { EntrySys } from './entry.js'
 
 /**
  * A wrapper object containing additional information for
diff --git a/lib/types/content-type.ts b/lib/types/content-type.ts
index f33421210..b3d6df658 100644
--- a/lib/types/content-type.ts
+++ b/lib/types/content-type.ts
@@ -1,7 +1,7 @@
-import { ContentfulCollection } from './collection'
-import { EntryFields } from './entry'
-import { SpaceLink, EnvironmentLink } from './link'
-import { BaseSys } from './sys'
+import { ContentfulCollection } from './collection.js'
+import { EntryFields } from './entry.js'
+import { SpaceLink, EnvironmentLink } from './link.js'
+import { BaseSys } from './sys.js'
 import type { BLOCKS, INLINES } from '@contentful/rich-text-types'
 
 /**
diff --git a/lib/types/entry.ts b/lib/types/entry.ts
index ce6848a1d..7be75e432 100644
--- a/lib/types/entry.ts
+++ b/lib/types/entry.ts
@@ -1,14 +1,14 @@
 import { Document as RichTextDocument } from '@contentful/rich-text-types'
-import { Asset } from './asset'
-import { ContentfulCollection } from './collection'
-import { ContentTypeLink, UnresolvedLink } from './link'
-import { LocaleCode } from './locale'
-import { Metadata } from './metadata'
-import { EntrySkeletonType } from './query'
-import { EntitySys } from './sys'
+import { Asset } from './asset.js'
+import { ContentfulCollection } from './collection.js'
+import { ContentTypeLink, UnresolvedLink } from './link.js'
+import { LocaleCode } from './locale.js'
+import { Metadata } from './metadata.js'
+import { EntrySkeletonType } from './query/index.js'
+import { EntitySys } from './sys.js'
 import { JsonArray, JsonObject } from 'type-fest'
-import { ResourceLink } from './resource-link'
-import { ChainModifiers } from './client'
+import { ResourceLink } from './resource-link.js'
+import { ChainModifiers } from './client.js'
 
 /**
  * System managed metadata for entries
diff --git a/lib/types/link.ts b/lib/types/link.ts
index fdfd1a613..28871a181 100644
--- a/lib/types/link.ts
+++ b/lib/types/link.ts
@@ -1,4 +1,4 @@
-import { ResourceLink } from './resource-link'
+import { ResourceLink } from './resource-link.js'
 
 /**
  * @category Link
diff --git a/lib/types/locale.ts b/lib/types/locale.ts
index c8734ddcf..555841997 100644
--- a/lib/types/locale.ts
+++ b/lib/types/locale.ts
@@ -1,5 +1,5 @@
-import { ContentfulCollection } from './collection'
-import { BaseSys } from './sys'
+import { ContentfulCollection } from './collection.js'
+import { BaseSys } from './sys.js'
 
 /**
  * @category Entity
diff --git a/lib/types/metadata.ts b/lib/types/metadata.ts
index 2e0785fb2..b1179eba7 100644
--- a/lib/types/metadata.ts
+++ b/lib/types/metadata.ts
@@ -1,4 +1,4 @@
-import { TagLink, TaxonomyConceptLink } from './link'
+import { TagLink, TaxonomyConceptLink } from './link.js'
 
 /**
  * User-controlled metadata
diff --git a/lib/types/query/equality.ts b/lib/types/query/equality.ts
index c66ef15ce..bb743296b 100644
--- a/lib/types/query/equality.ts
+++ b/lib/types/query/equality.ts
@@ -1,5 +1,5 @@
-import { EntryFields, EntryFieldType, EntryFieldTypes } from '../entry'
-import { ConditionalQueries, EntryFieldsConditionalQueries, EntrySkeletonType } from './util'
+import { EntryFields, EntryFieldType, EntryFieldTypes } from '../entry.js'
+import { ConditionalQueries, EntryFieldsConditionalQueries, EntrySkeletonType } from './util.js'
 
 type SupportedTypes =
   | EntryFields.Symbol
diff --git a/lib/types/query/existence.ts b/lib/types/query/existence.ts
index f44f31034..d29f1aba9 100644
--- a/lib/types/query/existence.ts
+++ b/lib/types/query/existence.ts
@@ -1,6 +1,6 @@
-import { EntryField, EntryFieldType } from '../entry'
-import { ConditionalFixedQueries, FieldsType, EntrySkeletonType } from './util'
-import { AssetDetails, AssetFile } from '../asset'
+import { EntryField, EntryFieldType } from '../entry.js'
+import { ConditionalFixedQueries, FieldsType, EntrySkeletonType } from './util.js'
+import { AssetDetails, AssetFile } from '../asset.js'
 
 /**
  * Check for existence of provided fields
diff --git a/lib/types/query/location.ts b/lib/types/query/location.ts
index 371d3d02f..1a3fa9c79 100644
--- a/lib/types/query/location.ts
+++ b/lib/types/query/location.ts
@@ -1,5 +1,5 @@
 import { ConditionalPick } from 'type-fest'
-import { EntryFieldTypes } from '../entry'
+import { EntryFieldTypes } from '../entry.js'
 
 type Types = EntryFieldTypes.Location | undefined
 
diff --git a/lib/types/query/order.ts b/lib/types/query/order.ts
index f9b22a25a..f44a5c27f 100644
--- a/lib/types/query/order.ts
+++ b/lib/types/query/order.ts
@@ -1,8 +1,8 @@
-import { EntrySkeletonType, FieldsType } from './util'
-import { EntryFields, EntryFieldType, EntryFieldTypes, EntrySys } from '../entry'
-import { AssetSys } from '../asset'
+import { EntrySkeletonType, FieldsType } from './util.js'
+import { EntryFields, EntryFieldType, EntryFieldTypes, EntrySys } from '../entry.js'
+import { AssetSys } from '../asset.js'
 import { ConditionalPick } from 'type-fest'
-import { TagSys } from '../tag'
+import { TagSys } from '../tag.js'
 
 export type SupportedTypes =
   | EntryFields.Symbol
diff --git a/lib/types/query/query.ts b/lib/types/query/query.ts
index ac6afd54a..9c819a2ff 100644
--- a/lib/types/query/query.ts
+++ b/lib/types/query/query.ts
@@ -1,35 +1,35 @@
-import { AssetDetails, AssetFile, AssetMimeType, AssetSys } from '../asset'
-import { ChainModifiers } from '../client'
-import { EntrySys } from '../entry'
-import { TagLink, TaxonomyConceptLink } from '../link'
-import { Metadata } from '../metadata'
-import { TagSys } from '../tag'
+import { AssetDetails, AssetFile, AssetMimeType, AssetSys } from '../asset.js'
+import { ChainModifiers } from '../client.js'
+import { EntrySys } from '../entry.js'
+import { TagLink, TaxonomyConceptLink } from '../link.js'
+import { Metadata } from '../metadata.js'
+import { TagSys } from '../tag.js'
 import {
   EntryFieldsEqualityFilter,
   EntryFieldsInequalityFilter,
   EqualityFilter,
   InequalityFilter,
-} from './equality'
-import { EntryFieldsExistenceFilter, ExistenceFilter } from './existence'
-import { LocationSearchFilters } from './location'
+} from './equality.js'
+import { EntryFieldsExistenceFilter, ExistenceFilter } from './existence.js'
+import { LocationSearchFilters } from './location.js'
 import {
   AssetOrderFilter,
   EntryOrderFilter,
   EntryOrderFilterWithFields,
   TagOrderFilter,
-} from './order'
-import { EntryFieldsRangeFilters, RangeFilters } from './range'
-import { ReferenceSearchFilters } from './reference'
-import { EntryFieldsFullTextSearchFilters, FullTextSearchFilters } from './search'
-import { AssetSelectFilter, EntrySelectFilter, EntrySelectFilterWithFields } from './select'
-import { EntryFieldsSetFilter } from './set'
-import { EntryFieldsSubsetFilters, SubsetFilters } from './subset'
+} from './order.js'
+import { EntryFieldsRangeFilters, RangeFilters } from './range.js'
+import { ReferenceSearchFilters } from './reference.js'
+import { EntryFieldsFullTextSearchFilters, FullTextSearchFilters } from './search.js'
+import { AssetSelectFilter, EntrySelectFilter, EntrySelectFilterWithFields } from './select.js'
+import { EntryFieldsSetFilter } from './set.js'
+import { EntryFieldsSubsetFilters, SubsetFilters } from './subset.js'
 import {
   ConditionalFixedQueries,
   ConditionalListQueries,
   EntrySkeletonType,
   FieldsType,
-} from './util'
+} from './util.js'
 
 export type FixedPagedOptions = {
   skip?: number
diff --git a/lib/types/query/range.ts b/lib/types/query/range.ts
index a7490829e..095cd4622 100644
--- a/lib/types/query/range.ts
+++ b/lib/types/query/range.ts
@@ -1,5 +1,5 @@
-import { EntryFields, EntryFieldType, EntryFieldTypes } from '../entry'
-import { ConditionalQueries, EntryFieldsConditionalQueries, EntrySkeletonType } from './util'
+import { EntryFields, EntryFieldType, EntryFieldTypes } from '../entry.js'
+import { ConditionalQueries, EntryFieldsConditionalQueries, EntrySkeletonType } from './util.js'
 
 type RangeFilterTypes = 'lt' | 'lte' | 'gt' | 'gte'
 
diff --git a/lib/types/query/reference.ts b/lib/types/query/reference.ts
index b8a895660..81a3249be 100644
--- a/lib/types/query/reference.ts
+++ b/lib/types/query/reference.ts
@@ -1,4 +1,4 @@
-import { EntryFieldTypes } from '../entry'
+import { EntryFieldTypes } from '../entry.js'
 import { ConditionalPick } from 'type-fest'
 
 type SupportedTypes =
diff --git a/lib/types/query/search.ts b/lib/types/query/search.ts
index e5e468e68..92c202d08 100644
--- a/lib/types/query/search.ts
+++ b/lib/types/query/search.ts
@@ -1,5 +1,5 @@
-import { EntryFields, EntryFieldTypes } from '../entry'
-import { ConditionalFixedQueries, FieldsType } from './util'
+import { EntryFields, EntryFieldTypes } from '../entry.js'
+import { ConditionalFixedQueries, FieldsType } from './util.js'
 
 type SupportedTypes =
   | EntryFields.Text
diff --git a/lib/types/query/select.ts b/lib/types/query/select.ts
index 9ce94a97d..b6f8a22c6 100644
--- a/lib/types/query/select.ts
+++ b/lib/types/query/select.ts
@@ -1,7 +1,7 @@
-import { FieldsType } from './util'
-import { EntrySys } from '../entry'
-import { AssetSys } from '../asset'
-import { Metadata } from '../metadata'
+import { FieldsType } from './util.js'
+import { EntrySys } from '../entry.js'
+import { AssetSys } from '../asset.js'
+import { Metadata } from '../metadata.js'
 
 export type SelectFilterPaths<
   Fields extends FieldsType,
diff --git a/lib/types/query/set.ts b/lib/types/query/set.ts
index 9e29d03b6..70781e773 100644
--- a/lib/types/query/set.ts
+++ b/lib/types/query/set.ts
@@ -1,5 +1,5 @@
-import { EntryFieldType, EntryFieldTypes } from '..'
-import { EntryFieldsConditionalListQueries } from './util'
+import { EntryFieldType, EntryFieldTypes } from '../index.js'
+import { EntryFieldsConditionalListQueries } from './util.js'
 
 type SupportedTypes =
   | EntryFieldTypes.Symbol
diff --git a/lib/types/query/subset.ts b/lib/types/query/subset.ts
index b15d63627..32f30b056 100644
--- a/lib/types/query/subset.ts
+++ b/lib/types/query/subset.ts
@@ -1,5 +1,5 @@
-import { EntryFields, EntryFieldType, EntryFieldTypes } from '..'
-import { ConditionalListQueries, EntryFieldsConditionalListQueries } from './util'
+import { EntryFields, EntryFieldType, EntryFieldTypes } from '../index.js'
+import { ConditionalListQueries, EntryFieldsConditionalListQueries } from './util.js'
 
 type SubsetFilterTypes = 'in' | 'nin'
 
diff --git a/lib/types/query/util.ts b/lib/types/query/util.ts
index 13aa2f962..077d8cd9c 100644
--- a/lib/types/query/util.ts
+++ b/lib/types/query/util.ts
@@ -1,5 +1,5 @@
 import { ConditionalPick } from 'type-fest'
-import { BaseFieldMap, EntryFieldType, EntryFieldTypes } from '../entry'
+import { BaseFieldMap, EntryFieldType, EntryFieldTypes } from '../entry.js'
 
 /**
  * @category Entity
diff --git a/lib/types/space.ts b/lib/types/space.ts
index 5ab03a3e5..852dc6dab 100644
--- a/lib/types/space.ts
+++ b/lib/types/space.ts
@@ -1,5 +1,5 @@
-import { Locale } from './locale'
-import { BaseSys } from './sys'
+import { Locale } from './locale.js'
+import { BaseSys } from './sys.js'
 
 /**
  * System managed metadata for spaces
diff --git a/lib/types/sync.ts b/lib/types/sync.ts
index 82f08d350..98d58d1e8 100644
--- a/lib/types/sync.ts
+++ b/lib/types/sync.ts
@@ -1,9 +1,9 @@
-import { Asset } from './asset'
-import { Entry } from './entry'
-import { EntitySys } from './sys'
-import { EntrySkeletonType } from './query'
-import { LocaleCode } from './locale'
-import { ChainModifiers } from './client'
+import { Asset } from './asset.js'
+import { Entry } from './entry.js'
+import { EntitySys } from './sys.js'
+import { EntrySkeletonType } from './query/index.js'
+import { LocaleCode } from './locale.js'
+import { ChainModifiers } from './client.js'
 
 /**
  * @category Sync
diff --git a/lib/types/sys.ts b/lib/types/sys.ts
index 4ae93d593..495e863c7 100644
--- a/lib/types/sys.ts
+++ b/lib/types/sys.ts
@@ -1,6 +1,6 @@
 import { ContentSourceMapsLookup, CPAContentSourceMaps } from '@contentful/content-source-maps'
-import { EntryFields } from './entry'
-import { EnvironmentLink, SpaceLink } from './link'
+import { EntryFields } from './entry.js'
+import { EnvironmentLink, SpaceLink } from './link.js'
 
 /**
  * Definition of common part of system managed metadata
diff --git a/lib/types/tag.ts b/lib/types/tag.ts
index adaaee5ac..f1ce3f958 100644
--- a/lib/types/tag.ts
+++ b/lib/types/tag.ts
@@ -1,6 +1,6 @@
-import { EntitySys } from './sys'
-import { ContentfulCollection } from './collection'
-import { UserLink } from './link'
+import { EntitySys } from './sys.js'
+import { ContentfulCollection } from './collection.js'
+import { UserLink } from './link.js'
 
 /**
  * System managed metadata for tags
diff --git a/lib/utils/client-helpers.ts b/lib/utils/client-helpers.ts
index f5ac820aa..7517895d9 100644
--- a/lib/utils/client-helpers.ts
+++ b/lib/utils/client-helpers.ts
@@ -1,4 +1,4 @@
-import { ChainModifiers } from '../types/client'
+import { ChainModifiers } from '../types/client.js'
 
 export type ChainOption<Modifiers extends ChainModifiers = ChainModifiers> = {
   withoutLinkResolution: ChainModifiers extends Modifiers
diff --git a/lib/utils/normalize-select.ts b/lib/utils/normalize-select.ts
index 7b99a30b5..a5dbfe014 100644
--- a/lib/utils/normalize-select.ts
+++ b/lib/utils/normalize-select.ts
@@ -1,4 +1,4 @@
-import getQuerySelectionSet from './query-selection-set'
+import getQuerySelectionSet from './query-selection-set.js'
 
 /*
  * sdk relies heavily on sys metadata