diff --git a/dist/index.js b/dist/index.js
index 74f102d..4dbae9b 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -447,7 +447,7 @@ function run() {
             }
             if (versions.length) {
                 const quality = core.getInput('dotnet-quality');
-                if (quality && !qualityOptions.includes(quality)) {
+                if (!qualityOptions.includes(quality)) {
                     throw new Error(`${quality} is not a supported value for 'dotnet-quality' option. Supported values are: daily, signed, validated, preview, ga.`);
                 }
                 let dotnetInstaller;
diff --git a/src/installer.ts b/src/installer.ts
index c5b20b5..7850510 100644
--- a/src/installer.ts
+++ b/src/installer.ts
@@ -7,6 +7,7 @@ import {chmodSync} from 'fs';
 import path from 'path';
 import semver from 'semver';
 import {IS_LINUX, IS_WINDOWS} from './utils';
+import {QualityOptions} from './setup-dotnet';
 
 export interface DotnetVersion {
   type: string;
@@ -111,7 +112,7 @@ export class DotnetVersionResolver {
 
 export class DotnetCoreInstaller {
   private version: string;
-  private quality: string;
+  private quality: QualityOptions;
   private static readonly installationDirectoryWindows = path.join(
     process.env['PROGRAMFILES'] + '',
     'dotnet'
@@ -146,7 +147,7 @@ export class DotnetCoreInstaller {
     }
   }
 
-  constructor(version: string, quality: string) {
+  constructor(version: string, quality: QualityOptions) {
     this.version = version;
     this.quality = quality;
   }
diff --git a/src/setup-dotnet.ts b/src/setup-dotnet.ts
index 367fa07..0646980 100644
--- a/src/setup-dotnet.ts
+++ b/src/setup-dotnet.ts
@@ -12,7 +12,7 @@ const qualityOptions = [
   'ga'
 ] as const;
 
-type QualityOptions = typeof qualityOptions[number];
+export type QualityOptions = typeof qualityOptions[number];
 
 export async function run() {
   try {
@@ -50,7 +50,7 @@ export async function run() {
     if (versions.length) {
       const quality = core.getInput('dotnet-quality') as QualityOptions;
 
-      if (quality && !qualityOptions.includes(quality)) {
+      if (!qualityOptions.includes(quality)) {
         throw new Error(
           `${quality} is not a supported value for 'dotnet-quality' option. Supported values are: daily, signed, validated, preview, ga.`
         );