diff --git a/__tests__/gpg.test.ts b/__tests__/gpg.test.ts
index 46b96be..b3e9477 100644
--- a/__tests__/gpg.test.ts
+++ b/__tests__/gpg.test.ts
@@ -72,7 +72,7 @@ describe('getDirs', () => {
 describe('configureAgent', () => {
   // eslint-disable-next-line jest/expect-expect
   it('configures GnuPG agent', async () => {
-    await gpg.configureAgent(gpg.agentConfig);
+    await gpg.configureAgent(await gpg.getHome(), gpg.agentConfig);
   });
 });
 
@@ -119,7 +119,7 @@ for (const userInfo of userInfos) {
     describe('presetPassphrase', () => {
       it('presets passphrase', async () => {
         await gpg.importKey(userInfo.pgp);
-        await gpg.configureAgent(gpg.agentConfig);
+        await gpg.configureAgent(await gpg.getHome(), gpg.agentConfig);
         for (const keygrip of await gpg.getKeygrips(userInfo.fingerprint)) {
           await gpg.presetPassphrase(keygrip, userInfo.passphrase).then(output => {
             expect(output).not.toEqual('');
@@ -131,7 +131,7 @@ for (const userInfo of userInfos) {
     describe('setTrustLevel', () => {
       it('set trust level', async () => {
         await gpg.importKey(userInfo.pgp);
-        await gpg.configureAgent(gpg.agentConfig);
+        await gpg.configureAgent(await gpg.getHome(), gpg.agentConfig);
         expect(() => {
           gpg.setTrustLevel(userInfo.keyID, '5');
         }).not.toThrow();
diff --git a/src/gpg.ts b/src/gpg.ts
index 7b4145b..0d692f9 100644
--- a/src/gpg.ts
+++ b/src/gpg.ts
@@ -20,17 +20,6 @@ export interface Dirs {
   homedir: string;
 }
 
-const getGnupgHome = async (): Promise<string> => {
-  if (process.env.GNUPGHOME) {
-    return process.env.GNUPGHOME;
-  }
-  let homedir: string = path.join(process.env.HOME || '', '.gnupg');
-  if (os.platform() == 'win32' && !process.env.HOME) {
-    homedir = path.join(process.env.USERPROFILE || '', '.gnupg');
-  }
-  return homedir;
-};
-
 const gpgConnectAgent = async (command: string): Promise<string> => {
   return await exec
     .getExecOutput(`gpg-connect-agent "${command}" /bye`, [], {
@@ -50,6 +39,26 @@ const gpgConnectAgent = async (command: string): Promise<string> => {
     });
 };
 
+export const getHome = async (): Promise<string> => {
+  let homedir = '';
+  if (process.env.GNUPGHOME) {
+    homedir = process.env.GNUPGHOME;
+  } else if (os.platform() == 'win32' && !process.env.HOME && process.env.USERPROFILE) {
+    homedir = path.join(process.env.USERPROFILE, '.gnupg');
+  } else if (process.env.HOME) {
+    homedir = path.join(process.env.HOME, '.gnupg');
+  } else {
+    homedir = (await getDirs()).homedir;
+  }
+  if (homedir.length == 0) {
+    throw new Error('Unable to determine GnuPG home directory');
+  }
+  if (!fs.existsSync(homedir)) {
+    fs.mkdirSync(homedir, {recursive: true});
+  }
+  return homedir;
+};
+
 export const getVersion = async (): Promise<Version> => {
   return await exec
     .getExecOutput('gpg', ['--version'], {
@@ -192,12 +201,8 @@ export const getKeygrip = async (fingerprint: string): Promise<string> => {
     });
 };
 
-export const configureAgent = async (config: string): Promise<void> => {
-  const gnupgHomeDir = await getGnupgHome();
-  if (!fs.existsSync(gnupgHomeDir)) {
-    fs.mkdirSync(gnupgHomeDir, {recursive: true});
-  }
-  const gpgAgentConf = path.join(gnupgHomeDir, 'gpg-agent.conf');
+export const configureAgent = async (homedir: string, config: string): Promise<void> => {
+  const gpgAgentConf = path.join(homedir, 'gpg-agent.conf');
   await fs.writeFile(gpgAgentConf, config, function (err) {
     if (err) throw err;
   });
diff --git a/src/main.ts b/src/main.ts
index 8e04296..591f23b 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -50,35 +50,32 @@ async function run(): Promise<void> {
       });
     });
 
-    if (inputs.passphrase && !inputs.fingerprint) {
-      // Set the passphrase for all subkeys
-
-      core.info('Configuring GnuPG agent');
-      await gpg.configureAgent(gpg.agentConfig);
-
-      await core.group(`Getting keygrips`, async () => {
-        for (const keygrip of await gpg.getKeygrips(fingerprint)) {
-          core.info(`Presetting passphrase for ${keygrip}`);
+    if (inputs.passphrase) {
+      await core.group(`Configuring GnuPG agent`, async () => {
+        const gpgHome = await gpg.getHome();
+        core.info(`GnuPG home: ${gpgHome}`);
+        await gpg.configureAgent(gpgHome, gpg.agentConfig);
+      });
+      if (!inputs.fingerprint) {
+        // Set the passphrase for all subkeys
+        await core.group(`Getting keygrips`, async () => {
+          for (const keygrip of await gpg.getKeygrips(fingerprint)) {
+            core.info(`Presetting passphrase for ${keygrip}`);
+            await gpg.presetPassphrase(keygrip, inputs.passphrase).then(stdout => {
+              core.debug(stdout);
+            });
+          }
+        });
+      } else {
+        // Set the passphrase only for the subkey specified in the input `fingerprint`
+        await core.group(`Getting keygrip for fingerprint`, async () => {
+          const keygrip = await gpg.getKeygrip(fingerprint);
+          core.info(`Presetting passphrase for key ${fingerprint} with keygrip ${keygrip}`);
           await gpg.presetPassphrase(keygrip, inputs.passphrase).then(stdout => {
             core.debug(stdout);
           });
-        }
-      });
-    }
-
-    if (inputs.passphrase && inputs.fingerprint) {
-      // Set the passphrase only for the subkey specified in the input `fingerprint`
-
-      core.info('Configuring GnuPG agent');
-      await gpg.configureAgent(gpg.agentConfig);
-
-      await core.group(`Getting keygrip for fingerprint`, async () => {
-        const keygrip = await gpg.getKeygrip(fingerprint);
-        core.info(`Presetting passphrase for key ${fingerprint} with keygrip ${keygrip}`);
-        await gpg.presetPassphrase(keygrip, inputs.passphrase).then(stdout => {
-          core.debug(stdout);
         });
-      });
+      }
     }
 
     if (inputs.trustLevel) {