diff --git a/lib/util/fs/index.ts b/lib/util/fs/index.ts
index 68c16d04e180a6b57f43a5ebddf71bc73685bdd6..b0c41376fac38acce3b8bdb725b9d97d77e86f58 100644
--- a/lib/util/fs/index.ts
+++ b/lib/util/fs/index.ts
@@ -29,7 +29,7 @@ export async function readLocalFile(
 ): Promise<string | null>;
 export async function readLocalFile(
   fileName: string,
-  encoding?: string
+  encoding?: BufferEncoding
 ): Promise<string | Buffer | null> {
   const localFileName = ensureLocalPath(fileName);
   try {
@@ -263,13 +263,16 @@ export async function readCacheFile(
 ): Promise<string>;
 export function readCacheFile(
   fileName: string,
-  encoding?: string
+  encoding?: BufferEncoding
 ): Promise<string | Buffer> {
   const fullPath = ensureCachePath(fileName);
   return encoding ? fs.readFile(fullPath, encoding) : fs.readFile(fullPath);
 }
 
-export function outputCacheFile(file: string, data: unknown): Promise<void> {
+export function outputCacheFile(
+  file: string,
+  data: string | NodeJS.ArrayBufferView
+): Promise<void> {
   const filePath = ensureCachePath(file);
   return fs.outputFile(filePath, data);
 }
@@ -281,7 +284,7 @@ export async function readSystemFile(
 ): Promise<string>;
 export function readSystemFile(
   fileName: string,
-  encoding?: string
+  encoding?: BufferEncoding
 ): Promise<string | Buffer> {
   return encoding ? fs.readFile(fileName, encoding) : fs.readFile(fileName);
 }
diff --git a/lib/util/git/private-key.ts b/lib/util/git/private-key.ts
index 06a15b407c4df415ff315a3b795a72c155e320e5..64cd923b21dff674a2b8e193c21bec992be28b4c 100644
--- a/lib/util/git/private-key.ts
+++ b/lib/util/git/private-key.ts
@@ -25,7 +25,7 @@ async function importKey(): Promise<void> {
     return;
   }
   const keyFileName = upath.join(os.tmpdir() + '/git-private.key');
-  await fs.outputFile(keyFileName, gitPrivateKey);
+  await fs.outputFile(keyFileName, gitPrivateKey!);
   const { stdout, stderr } = await exec(`gpg --import ${keyFileName}`);
   logger.debug({ stdout, stderr }, 'Private key import result');
   keyId = `${stdout}${stderr}`
diff --git a/package.json b/package.json
index c7e0811ba76a442222b2815d2b379747759acc43..198879ab849f6ce264cd84152f5fe5deafda91a6 100644
--- a/package.json
+++ b/package.json
@@ -260,7 +260,7 @@
     "@types/conventional-commits-detector": "1.0.0",
     "@types/diff": "5.0.2",
     "@types/eslint": "8.4.10",
-    "@types/fs-extra": "9.0.13",
+    "@types/fs-extra": "11.0.1",
     "@types/git-url-parse": "9.0.1",
     "@types/github-url-from-git": "1.5.1",
     "@types/global-agent": "2.1.1",
diff --git a/yarn.lock b/yarn.lock
index cdd41e6689a714f1b82c971514fdc03a2d7466b2..5f26060241ce2ddfd545c9c3b3991a4bb7c75e9d 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2893,11 +2893,12 @@
   resolved "https://registry.yarnpkg.com/@types/estree/-/estree-1.0.0.tgz#5fb2e536c1ae9bf35366eed879e827fa59ca41c2"
   integrity sha512-WulqXMDUTYAXCjZnk6JtIHPigp55cVtDgDrO2gHRwhyJto21+1zbVCtOYB2L1F9w4qCQ0rOGWBnBe0FNTiEJIQ==
 
-"@types/fs-extra@9.0.13":
-  version "9.0.13"
-  resolved "https://registry.yarnpkg.com/@types/fs-extra/-/fs-extra-9.0.13.tgz#7594fbae04fe7f1918ce8b3d213f74ff44ac1f45"
-  integrity sha512-nEnwB++1u5lVDM2UI4c1+5R+FYaKfaAzS4OococimjVm3nQw3TuzH5UNsocrcTBbhnerblyHj4A49qXbIiZdpA==
+"@types/fs-extra@11.0.1":
+  version "11.0.1"
+  resolved "https://registry.yarnpkg.com/@types/fs-extra/-/fs-extra-11.0.1.tgz#f542ec47810532a8a252127e6e105f487e0a6ea5"
+  integrity sha512-MxObHvNl4A69ofaTRU8DFqvgzzv8s9yRtaPPm5gud9HDNvpB3GPQFvNuTWAI59B9huVGV5jXYJwbCsmBsOGYWA==
   dependencies:
+    "@types/jsonfile" "*"
     "@types/node" "*"
 
 "@types/git-url-parse@9.0.1":
@@ -2979,6 +2980,13 @@
   resolved "https://registry.yarnpkg.com/@types/json5/-/json5-0.0.29.tgz#ee28707ae94e11d2b827bcbe5270bcea7f3e71ee"
   integrity sha512-dRLjCWHYg4oaA77cxO64oO+7JwCwnIzkZPdrrC71jQmQtlhM556pwKo5bUzqvZndkVbeFLIIi+9TC40JNF5hNQ==
 
+"@types/jsonfile@*":
+  version "6.1.1"
+  resolved "https://registry.yarnpkg.com/@types/jsonfile/-/jsonfile-6.1.1.tgz#ac84e9aefa74a2425a0fb3012bdea44f58970f1b"
+  integrity sha512-GSgiRCVeapDN+3pqA35IkQwasaCh/0YFH5dEF6S88iDvEn901DjOeH3/QPY+XYP1DFzDZPvIvfeEgk+7br5png==
+  dependencies:
+    "@types/node" "*"
+
 "@types/keyv@^3.1.4":
   version "3.1.4"
   resolved "https://registry.yarnpkg.com/@types/keyv/-/keyv-3.1.4.tgz#3ccdb1c6751b0c7e52300bcdacd5bcbf8faa75b6"