diff --git a/__tests__/csv-escape.test.ts b/__tests__/csv-escape.test.ts
index 6c3acfa..b0abcfc 100644
--- a/__tests__/csv-escape.test.ts
+++ b/__tests__/csv-escape.test.ts
@@ -1,6 +1,6 @@
 import {describe, expect, test} from 'vitest'
 
-import {csvEscape} from '../src/list-format/csv-escape'
+import {csvEscape} from '../src/list-format/csv-escape.ts'
 
 describe('csvEscape() backslash escapes every character except subset of definitely safe characters', () => {
   test('simple filename should not be modified', () => {
diff --git a/__tests__/filter.test.ts b/__tests__/filter.test.ts
index 8e96d71..add807a 100644
--- a/__tests__/filter.test.ts
+++ b/__tests__/filter.test.ts
@@ -1,7 +1,7 @@
 import {describe, expect, test} from 'vitest'
 
-import {File, ChangeStatus} from '../src/file'
-import {Filter} from '../src/filter'
+import {File, ChangeStatus} from '../src/file.ts'
+import {Filter} from '../src/filter.ts'
 
 describe('yaml filter parsing tests', () => {
   test('throws if yaml is not a dictionary', () => {
diff --git a/__tests__/git.test.ts b/__tests__/git.test.ts
index c1aa8ed..cb6f85a 100644
--- a/__tests__/git.test.ts
+++ b/__tests__/git.test.ts
@@ -1,7 +1,7 @@
 import {describe, expect, test} from 'vitest'
 
-import {ChangeStatus} from '../src/file'
-import * as git from '../src/git'
+import {ChangeStatus} from '../src/file.ts'
+import * as git from '../src/git.ts'
 
 describe('parsing output of the git diff command', () => {
   test('parseGitDiffOutput returns files with correct change status', () => {
diff --git a/__tests__/shell-escape.test.ts b/__tests__/shell-escape.test.ts
index 75f310e..56d6f17 100644
--- a/__tests__/shell-escape.test.ts
+++ b/__tests__/shell-escape.test.ts
@@ -1,6 +1,6 @@
 import {describe, expect, test} from 'vitest'
 
-import {backslashEscape, shellEscape} from '../src/list-format/shell-escape'
+import {backslashEscape, shellEscape} from '../src/list-format/shell-escape.ts'
 
 describe('escape() backslash escapes every character except subset of definitely safe characters', () => {
   test('simple filename should not be modified', () => {
diff --git a/src/filter.ts b/src/filter.ts
index 8949e24..f9ea1b6 100644
--- a/src/filter.ts
+++ b/src/filter.ts
@@ -1,7 +1,7 @@
 import * as jsyaml from 'js-yaml'
 import micromatch from 'micromatch'
 
-import {File} from './file'
+import {File} from './file.ts'
 
 // Type definition of object we expect to load from YAML
 type FilterYaml = Record<string, FilterItemYaml>
diff --git a/src/git.ts b/src/git.ts
index 5f96890..59a5ea4 100644
--- a/src/git.ts
+++ b/src/git.ts
@@ -1,7 +1,7 @@
 import * as core from '@actions/core'
 
-import exec from './exec'
-import {File, ChangeStatus} from './file'
+import exec from './exec.ts'
+import {File, ChangeStatus} from './file.ts'
 
 export const NULL_SHA = '0000000000000000000000000000000000000000'
 export const HEAD = 'HEAD'
diff --git a/src/main.ts b/src/main.ts
index 51dcc72..7142fde 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -4,11 +4,11 @@ import * as core from '@actions/core'
 import * as github from '@actions/github'
 import {PullRequest, PushEvent} from '@octokit/webhooks-types'
 
-import {File, ChangeStatus} from './file'
-import {Filter, FilterResults} from './filter'
-import * as git from './git'
-import {csvEscape} from './list-format/csv-escape'
-import {backslashEscape, shellEscape} from './list-format/shell-escape'
+import {File, ChangeStatus} from './file.ts'
+import {Filter, FilterResults} from './filter.ts'
+import * as git from './git.ts'
+import {csvEscape} from './list-format/csv-escape.ts'
+import {backslashEscape, shellEscape} from './list-format/shell-escape.ts'
 
 type ExportFormat = 'none' | 'csv' | 'json' | 'shell' | 'escape'