diff --git a/bin/install.js b/bin/install.js
index 5f5db615..e469e386 100755
--- a/bin/install.js
+++ b/bin/install.js
@@ -12,6 +12,7 @@ import {
 } from 'node:fs';
 import { dirname, join, resolve } from 'node:path';
 import { fileURLToPath } from 'node:url';
+import { parse, stringify } from 'comment-json';
 import sortPackageJson from 'sort-package-json';
 
 const projectPackageJsonPath = join(process.cwd(), 'package.json');
@@ -208,6 +209,42 @@ for (const {
     // Always overwrite tsconfig.json
     if (templateFileName === 'tsconfig.json') {
       overwriteExistingFile = true;
+
+      const projectTsConfig = parse(readFileSync(filePathInProject, 'utf-8'));
+      const templateTsConfig = parse(readFileSync(templateFilePath, 'utf-8'));
+
+      if (
+        projectTsConfig &&
+        templateTsConfig &&
+        typeof projectTsConfig === 'object' &&
+        !Array.isArray(projectTsConfig) &&
+        projectTsConfig.compilerOptions &&
+        typeof projectTsConfig.compilerOptions === 'object' &&
+        !Array.isArray(projectTsConfig.compilerOptions) &&
+        projectTsConfig.compilerOptions.paths &&
+        typeof projectTsConfig.compilerOptions.paths === 'object' &&
+        typeof templateTsConfig === 'object' &&
+        !Array.isArray(templateTsConfig) &&
+        templateTsConfig.compilerOptions &&
+        typeof templateTsConfig.compilerOptions === 'object' &&
+        !Array.isArray(templateTsConfig.compilerOptions) &&
+        !templateTsConfig.compilerOptions.paths
+      ) {
+        templateTsConfig.compilerOptions.paths =
+          projectTsConfig.compilerOptions.paths;
+
+        templateTsConfig.compilerOptions.paths = {
+          ...projectTsConfig.compilerOptions.paths,
+          ...templateTsConfig.compilerOptions.paths,
+        };
+      }
+
+      writeFileSync(
+        filePathInProject,
+        `${stringify(templateTsConfig, null, 2)}\n`,
+      );
+      console.log('✅ Done merging default tsconfig.json');
+      continue;
     }
 
     if (!overwriteExistingFile) {
diff --git a/package.json b/package.json
index 5cc45a00..379f8561 100644
--- a/package.json
+++ b/package.json
@@ -41,6 +41,7 @@
     "@next/eslint-plugin-next": "14.2.4",
     "@typescript-eslint/eslint-plugin": "8.0.0-alpha.30",
     "@typescript-eslint/parser": "8.0.0-alpha.30",
+    "comment-json": "^4.2.3",
     "eslint-config-flat-gitignore": "0.1.5",
     "eslint-import-resolver-typescript": "3.6.1",
     "eslint-plugin-import-x": "0.5.1",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index db5d995c..245b583a 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -32,6 +32,9 @@ importers:
       '@typescript-eslint/parser':
         specifier: 8.0.0-alpha.30
         version: 8.0.0-alpha.30(eslint@9.5.0)(typescript@5.5.2)
+      comment-json:
+        specifier: ^4.2.3
+        version: 4.2.3
       eslint:
         specifier: ^9.5.0
         version: 9.5.0
@@ -510,6 +513,9 @@ packages:
     resolution: {integrity: sha512-itaWrbYbqpGXkGhZPGUulwnhVf5Hpy1xiCFsGqyIGglbBxmG5vSjxQen3/WGOjPpNEv1RtBLKxbmVXm8HpJStQ==}
     engines: {node: '>= 0.4'}
 
+  array-timsort@1.0.3:
+    resolution: {integrity: sha512-/+3GRL7dDAGEfM6TseQk/U+mi18TU2Ms9I3UlLdUMhz2hbvGNTKdj9xniwXfUqgYhHxRx0+8UnKkvlNwVU+cWQ==}
+
   array-union@2.1.0:
     resolution: {integrity: sha512-HGyxoOTYUyCM6stUe6EJgnd4EoewAI7zMdfqO+kGjnlZmBDz/cR5pf8r/cR4Wq60sL/p0IkcjUEEPwS3GFrIyw==}
     engines: {node: '>=8'}
@@ -634,6 +640,10 @@ packages:
   commander@2.20.3:
     resolution: {integrity: sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ==}
 
+  comment-json@4.2.3:
+    resolution: {integrity: sha512-SsxdiOf064DWoZLH799Ata6u7iV658A11PlWtZATDlXPpKGJnbJZ5Z24ybixAi+LUUqJ/GKowAejtC5GFUG7Tw==}
+    engines: {node: '>= 6'}
+
   concat-map@0.0.1:
     resolution: {integrity: sha512-/Srv4dswyQNBfohGpz9o6Yb3Gz3SrUDqBH5rTuhGR7ahtlbYKnVxw2bCFMRljaA7EXHaXZ8wsHdodFvbkhKmqg==}
 
@@ -643,6 +653,9 @@ packages:
   core-js-compat@3.37.1:
     resolution: {integrity: sha512-9TNiImhKvQqSUkOvk/mMRZzOANTiEVC7WaBNhHcKM7x+/5E1l5NvsysR19zuDQScE8k+kfQXWRN3AtS/eOSHpg==}
 
+  core-util-is@1.0.3:
+    resolution: {integrity: sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ==}
+
   cosmiconfig@9.0.0:
     resolution: {integrity: sha512-itvL5h8RETACmOTFc4UfIyB2RfEHi71Ax6E/PivVxq9NseKbOWpeyHEOIbmAw1rs8Ak0VursQNww7lf7YtUwzg==}
     engines: {node: '>=14'}
@@ -963,6 +976,11 @@ packages:
     resolution: {integrity: sha512-MWkrWZbJsL2UwnjxTX3gG8FneachS/Mwg7tdGXce011sJd5b0JG54vat5KHnfSBODZ3Wvzd2WnjxyzsRoVv+ww==}
     engines: {node: ^18.18.0 || ^20.9.0 || >=21.1.0}
 
+  esprima@4.0.1:
+    resolution: {integrity: sha512-eGuFFw7Upda+g4p+QHvnW0RyTX/SVeJBDM/gCtMARO0cLuT2HcEKnTPvhjV6aGeqrCB/sbNop0Kszm0jsaWU4A==}
+    engines: {node: '>=4'}
+    hasBin: true
+
   esquery@1.5.0:
     resolution: {integrity: sha512-YQLXUplAwJgCydQ78IMJywZCceoqk1oH01OERdSAJc/7U2AylwjhSCLDEtqwg811idIS/9fIU5GjG73IgjKMVg==}
     engines: {node: '>=0.10'}
@@ -1153,6 +1171,10 @@ packages:
     resolution: {integrity: sha512-EykJT/Q1KjTWctppgIAgfSO0tKVuZUjhgMr17kqTumMl6Afv3EISleU7qZUzoXDFTAHTDC4NOoG/ZxU3EvlMPQ==}
     engines: {node: '>=8'}
 
+  has-own-prop@2.0.0:
+    resolution: {integrity: sha512-Pq0h+hvsVm6dDEa8x82GnLSYHOzNDt7f0ddFa3FqcQlgzEiptPqL+XrOJNavjOzSYiYWIrgeVYYgGlLmnxwilQ==}
+    engines: {node: '>=8'}
+
   has-property-descriptors@1.0.2:
     resolution: {integrity: sha512-55JNKuIW+vq4Ke1BjOTjM2YctQIvCT7GFzHwmfZPGo5wnrgkid0YQtnAleFSqumZm4az3n2BS+erby5ipJdgrg==}
 
@@ -1720,6 +1742,10 @@ packages:
     resolution: {integrity: sha512-qx+xQGZVsy55CH0a1hiVwHmqjLryfh7wQyF5HO07XJ9f7dQMY/gPQHhlyDkIzJKC+x2fUCpCcUODUUUFrm7SHA==}
     hasBin: true
 
+  repeat-string@1.6.1:
+    resolution: {integrity: sha512-PV0dzCYDNfRi1jCDbJzpW7jNNDRuCOG/jI5ctQcGKt/clZD+YcPS3yIlWuTJMmESC8aevCFmWJy5wjAFgNqN6w==}
+    engines: {node: '>=0.10'}
+
   require-from-string@2.0.2:
     resolution: {integrity: sha512-Xf0nWe6RseziFMu+Ap9biiUbmplq6S9/p+7w7YXP/JBHhrUDDUhwa+vANyubuqfZWTveU//DYVGsDG7RKL/vEw==}
     engines: {node: '>=0.10.0'}
@@ -2568,6 +2594,8 @@ snapshots:
       get-intrinsic: 1.2.4
       is-string: 1.0.7
 
+  array-timsort@1.0.3: {}
+
   array-union@2.1.0: {}
 
   array.prototype.findlast@1.2.5:
@@ -2714,6 +2742,14 @@ snapshots:
 
   commander@2.20.3: {}
 
+  comment-json@4.2.3:
+    dependencies:
+      array-timsort: 1.0.3
+      core-util-is: 1.0.3
+      esprima: 4.0.1
+      has-own-prop: 2.0.0
+      repeat-string: 1.6.1
+
   concat-map@0.0.1: {}
 
   convert-source-map@2.0.0: {}
@@ -2722,6 +2758,8 @@ snapshots:
     dependencies:
       browserslist: 4.23.0
 
+  core-util-is@1.0.3: {}
+
   cosmiconfig@9.0.0(typescript@5.5.2):
     dependencies:
       env-paths: 2.2.1
@@ -3249,6 +3287,8 @@ snapshots:
       acorn-jsx: 5.3.2(acorn@8.11.3)
       eslint-visitor-keys: 4.0.0
 
+  esprima@4.0.1: {}
+
   esquery@1.5.0:
     dependencies:
       estraverse: 5.3.0
@@ -3441,6 +3481,8 @@ snapshots:
 
   has-flag@4.0.0: {}
 
+  has-own-prop@2.0.0: {}
+
   has-property-descriptors@1.0.2:
     dependencies:
       es-define-property: 1.0.0
@@ -3973,6 +4015,8 @@ snapshots:
     dependencies:
       jsesc: 0.5.0
 
+  repeat-string@1.6.1: {}
+
   require-from-string@2.0.2: {}
 
   resolve-from@4.0.0: {}