diff --git a/src/functions.ts b/src/functions.ts
index 34332e6..a39138c 100644
--- a/src/functions.ts
+++ b/src/functions.ts
@@ -1,11 +1,16 @@
 import * as core from '@actions/core'
 import * as fs from 'fs'
-import retry = require('async-retry')
-import semver = require('semver')
+import * as tc from '@actions/tool-cache'
+import {GitHub} from '@actions/github/lib/utils'
+import retry from 'async-retry'
+import semver from 'semver'
 
 const NEXTFLOW_REPO = {owner: 'nextflow-io', repo: 'nextflow'}
 
-async function all_nf_releases(ok) {
+// HACK Private but I want to test this
+export async function all_nf_releases(
+  ok: InstanceType<typeof GitHub>
+): Promise<object> {
   return await ok.paginate(
     ok.rest.repos.listReleases,
     NEXTFLOW_REPO,
@@ -13,7 +18,10 @@ async function all_nf_releases(ok) {
   )
 }
 
-async function latest_stable_release_data(ok) {
+// HACK Private but I want to test this
+export async function latest_stable_release_data(
+  ok: InstanceType<typeof GitHub>
+): Promise<object> {
   const {data: stable_release} = await ok.rest.repos.getLatestRelease(
     NEXTFLOW_REPO
   )
@@ -21,9 +29,12 @@ async function latest_stable_release_data(ok) {
   return stable_release
 }
 
-export async function release_data(version, ok) {
+export async function release_data(
+  version: string,
+  ok: InstanceType<typeof GitHub>
+): Promise<object> {
   // Setup tag-based filtering
-  let filter = r => {
+  let filter = (r: object): boolean => {
     return semver.satisfies(r.tag_name, version, true)
   }
 
@@ -32,7 +43,8 @@ export async function release_data(version, ok) {
   if (version.includes('latest')) {
     if (version.includes('-everything')) {
       // No filtering
-      filter = r => {
+      // eslint-disable-next-line @typescript-eslint/no-unused-vars
+      filter = (r: object) => {
         return true
       }
     } else if (version.includes('-edge')) {
@@ -50,7 +62,7 @@ export async function release_data(version, ok) {
   // Get all the releases
   const all_releases = await all_nf_releases(ok)
 
-  let matching_releases = all_releases.filter(filter)
+  const matching_releases = all_releases.filter(filter)
 
   matching_releases.sort(function (x, y) {
     semver.compare(x.tag_name, y.tag_name, true)
@@ -59,13 +71,13 @@ export async function release_data(version, ok) {
   return matching_releases[0]
 }
 
-export function nextflow_bin_url(release, get_all) {
+export function nextflow_bin_url(release, get_all: boolean): string {
   const release_assets = release.assets
   const all_asset = release_assets.filter(a => {
     return a.browser_download_url.endsWith('-all')
   })[0]
   const regular_asset = release_assets.filter(a => {
-    return a.name == 'nextflow'
+    return a.name === 'nextflow'
   })[0]
 
   const dl_asset = get_all ? all_asset : regular_asset
@@ -73,9 +85,13 @@ export function nextflow_bin_url(release, get_all) {
   return dl_asset.browser_download_url
 }
 
-export async function install_nextflow(url, version) {
+export async function install_nextflow(
+  url: string,
+  version: string
+): Promise<string> {
   core.debug(`Downloading Nextflow from ${url}`)
   const nf_dl_path = await retry(
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
     async bail => {
       return await tc.downloadTool(url)
     },
diff --git a/src/main.ts b/src/main.ts
index 495a20d..a141779 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -3,9 +3,9 @@ import * as exec from '@actions/exec'
 import * as fs from 'fs'
 import * as github from '@actions/github'
 import * as tc from '@actions/tool-cache'
-import {release_data, nextflow_bin_url, install_nextflow} from './functions'
+import {install_nextflow, nextflow_bin_url, release_data} from './functions'
 
-async function run() {
+async function run(): Promise<void> {
   // Set environment variables
   core.exportVariable('CAPSULE_LOG', 'none')
 
@@ -20,19 +20,19 @@ async function run() {
   let octokit = {}
   try {
     octokit = github.getOctokit(token)
-  } catch (e: any) {
+  } catch (e) {
     core.setFailed(
       `Could not authenticate to GitHub Releases API with provided token\n${e.message}`
     )
   }
 
   // Get the release info for the desired release
-  let release: any = {}
+  let release = {}
   try {
     release = await release_data(version, octokit)
     resolved_version = release.tag_name
     core.info(`Input version '${version}' resolved to Nextflow ${release.name}`)
-  } catch (e: any) {
+  } catch (e) {
     core.setFailed(
       `Could not retrieve Nextflow release matching ${version}.\n${e.message}`
     )
@@ -43,7 +43,7 @@ async function run() {
   try {
     url = nextflow_bin_url(release, get_all)
     core.info(`Preparing to download from ${url}`)
-  } catch (e: any) {
+  } catch (e) {
     core.setFailed(`Could not parse the download URL\n${e.message}`)
   }
   try {
@@ -66,14 +66,14 @@ async function run() {
     core.addPath(nf_path)
 
     core.info(`Downloaded \`nextflow\` to ${nf_path} and added to PATH`)
-  } catch (e: any) {
+  } catch (e) {
     core.setFailed(e.message)
   }
 
   // Run Nextflow so it downloads its dependencies
   try {
-    const nf_exit_code = await exec.exec('nextflow', ['help'])
-  } catch (e: any) {
+    await exec.exec('nextflow', ['help'])
+  } catch (e) {
     core.warning(
       'Nextflow appears to have installed correctly, but an error was thrown while running it.'
     )