diff --git a/package.json b/package.json
index f04e3e0f..48a85a85 100644
--- a/package.json
+++ b/package.json
@@ -45,6 +45,7 @@
     "@semantic-release/git": "10.0.1",
     "@semantic-release/github": "8.0.7",
     "@semantic-release/npm": "9.0.2",
+    "@tsconfig/node16": "1.0.3",
     "@types/node": "16.18.23",
     "@typescript-eslint/eslint-plugin": "5.59.0",
     "@typescript-eslint/parser": "5.59.0",
diff --git a/src/input.ts b/src/input.ts
index 18157b77..9ae45f69 100644
--- a/src/input.ts
+++ b/src/input.ts
@@ -31,7 +31,9 @@ class Input {
       ? new RegExp(envRegexInput)
       : this.options.envRegex;
     this._environmentVariables = new Map(
-      Object.entries(process.env).filter(([key]) => envRegex.test(key))
+      Object.entries(process.env)
+        .filter(([key]) => envRegex.test(key))
+        .filter((pair): pair is [string, string] => pair[1] !== undefined)
     );
 
     this.token = this.get(
diff --git a/src/renovate.ts b/src/renovate.ts
index aed10203..f73a249f 100644
--- a/src/renovate.ts
+++ b/src/renovate.ts
@@ -22,12 +22,13 @@ class Renovate {
       .map((e) => `--env ${e.key}`)
       .concat([`--env ${this.input.token.key}=${this.input.token.value}`]);
 
-    if (this.input.configurationFile() !== null) {
-      const baseName = path.basename(this.input.configurationFile().value);
+    const configurationFile = this.input.configurationFile();
+    if (configurationFile !== null) {
+      const baseName = path.basename(configurationFile.value);
       const mountPath = path.join(this.configFileMountDir, baseName);
       dockerArguments.push(
-        `--env ${this.input.configurationFile().key}=${mountPath}`,
-        `--volume ${this.input.configurationFile().value}:${mountPath}`
+        `--env ${configurationFile.key}=${mountPath}`,
+        `--volume ${configurationFile.value}:${mountPath}`
       );
     }
 
diff --git a/tsconfig.json b/tsconfig.json
index b0369556..022f92d7 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,10 +1,6 @@
 {
+  "extends": "@tsconfig/node16/tsconfig.json",
   "compilerOptions": {
-    "target": "es2020",
-    "module": "commonjs",
-    "moduleResolution": "node",
-    "resolveJsonModule": true,
-    "esModuleInterop": true,
     "allowSyntheticDefaultImports": true,
     "allowJs": true,
     "outDir": "dist"
diff --git a/yarn.lock b/yarn.lock
index 225d616f..03867606 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -726,7 +726,7 @@
   resolved "https://registry.yarnpkg.com/@tsconfig/node14/-/node14-1.0.3.tgz#e4386316284f00b98435bf40f72f75a09dabf6c1"
   integrity sha512-ysT8mhdixWK6Hw3i1V2AeRqZ5WfXg1G43mqoYlM2nc6388Fq5jcXyr5mRsqViLx/GJYdoL0bfXD8nmF+Zn/Iow==
 
-"@tsconfig/node16@^1.0.2":
+"@tsconfig/node16@1.0.3", "@tsconfig/node16@^1.0.2":
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/@tsconfig/node16/-/node16-1.0.3.tgz#472eaab5f15c1ffdd7f8628bd4c4f753995ec79e"
   integrity sha512-yOlFc+7UtL/89t2ZhjPvvB/DeAr3r+Dq58IgzsFkOAvVC6NMJXmCGjbptdXdR9qsX7pKcTL+s87FtYREi2dEEQ==