diff --git a/lib/setup-haskell.js b/lib/setup-haskell.js
index b8e48ed..0493ba6 100644
--- a/lib/setup-haskell.js
+++ b/lib/setup-haskell.js
@@ -18,13 +18,23 @@ var __importStar = (this && this.__importStar) || function (mod) {
 Object.defineProperty(exports, "__esModule", { value: true });
 const core = __importStar(require("@actions/core"));
 const installer_1 = require("./installer");
+const defaultGHCVersion = '8.6.5';
+const defualtCabalVersion = '3.0';
 function run() {
     return __awaiter(this, void 0, void 0, function* () {
         try {
             yield installer_1.cacheHaskellTool('/opt', 'ghc');
             yield installer_1.cacheHaskellTool('/opt', 'cabal');
             let ghcVersion = core.getInput('ghc-version');
+            if (!ghcVersion) {
+                ghcVersion = defaultGHCVersion;
+            }
             yield installer_1.findHaskellGHCVersion(ghcVersion);
+            let cabalVersion = core.getInput('cabal-version');
+            if (!cabalVersion) {
+                cabalVersion = defualtCabalVersion;
+            }
+            yield installer_1.findHaskellCabalVersion(cabalVersion);
         }
         catch (error) {
             core.setFailed(error.message);
diff --git a/src/installer.ts b/src/installer.ts
index b9b0fa5..e63a3e3 100644
--- a/src/installer.ts
+++ b/src/installer.ts
@@ -17,16 +17,10 @@ export async function cacheHaskellTool(installDir: string, tool: string) {
 }
 
 export async function findHaskellGHCVersion(version: string) {
-  if (!version) {
-    version = '8.6.5';
-  }
   return _findHaskellToolVersion('ghc', version);
 }
 
 export async function findHaskellCabalVersion(version: string) {
-  if (!version) {
-    version = '3.0';
-  }
   return _findHaskellToolVersion('cabal', version);
 }
 
diff --git a/src/setup-haskell.ts b/src/setup-haskell.ts
index c98045f..f7853a8 100644
--- a/src/setup-haskell.ts
+++ b/src/setup-haskell.ts
@@ -5,14 +5,24 @@ import {
   cacheHaskellTool
 } from './installer';
 
+const defaultGHCVersion = '8.6.5';
+const defualtCabalVersion = '3.0';
+
 async function run() {
   try {
     await cacheHaskellTool('/opt', 'ghc');
     await cacheHaskellTool('/opt', 'cabal');
+
     let ghcVersion = core.getInput('ghc-version');
+    if (!ghcVersion) {
+      ghcVersion = defaultGHCVersion;
+    }
     await findHaskellGHCVersion(ghcVersion);
 
     let cabalVersion = core.getInput('cabal-version');
+    if (!cabalVersion) {
+      cabalVersion = defualtCabalVersion;
+    }
     await findHaskellCabalVersion(cabalVersion);
   } catch (error) {
     core.setFailed(error.message);