diff --git a/README.md b/README.md
index f08569ab4..c8c143f25 100644
--- a/README.md
+++ b/README.md
@@ -590,6 +590,12 @@ Here's an explanation of the configuration options:
 | `security.enableSecurityCheck`   | Whether to perform security checks on files                                                                                  | `true`                 |
 | `tokenCount.encoding`            | Token count encoding for AI model context limits (e.g., `o200k_base`, `cl100k_base`)                                         | `"o200k_base"`         |
 
+The configuration file supports [JSON5](https://json5.org/) syntax, which allows:
+- Comments (both single-line and multi-line)
+- Trailing commas in objects and arrays
+- Unquoted property names
+- More relaxed string syntax
+
 Example configuration:
 
 ```json5
@@ -607,7 +613,7 @@ Example configuration:
     "showLineNumbers": false,
     "copyToClipboard": true,
     "topFilesLength": 5,
-    "includeEmptyDirectories": false
+    "includeEmptyDirectories": false,
   },
   "include": [
     "**/*"
@@ -619,14 +625,14 @@ Example configuration:
     "customPatterns": [
       "additional-folder",
       "**/*.log"
-    ]
+    ],
   },
   "security": {
     "enableSecurityCheck": true
   },
   "tokenCount": {
     "encoding": "o200k_base"
-  }
+  },
 }
 ```
 
diff --git a/biome.json b/biome.json
index c5cb7a9af..4b6ef7d7a 100644
--- a/biome.json
+++ b/biome.json
@@ -48,7 +48,11 @@
   },
   "json": {
     "parser": {
-      "allowComments": true
+      "allowComments": true,
+      "allowTrailingCommas": true
+    },
+    "formatter": {
+      "enabled": false
     }
   }
 }
diff --git a/package-lock.json b/package-lock.json
index d09c63bd7..2ddfdc25b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -22,6 +22,7 @@
         "iconv-lite": "^0.6.3",
         "istextorbinary": "^9.5.0",
         "jschardet": "^3.1.4",
+        "json5": "^2.2.3",
         "log-update": "^6.1.0",
         "minimatch": "^10.0.1",
         "picocolors": "^1.1.1",
@@ -2954,7 +2955,6 @@
       "version": "2.2.3",
       "resolved": "https://registry.npmjs.org/json5/-/json5-2.2.3.tgz",
       "integrity": "sha512-XmOWe7eyHYH14cLdVPoyg+GOH3rYX++KpzrylJwSW98t3Nk+U8XOl8FWKOgwtzdb8lXGf6zYwDUzeHMWfxasyg==",
-      "dev": true,
       "license": "MIT",
       "bin": {
         "json5": "lib/cli.js"
diff --git a/package.json b/package.json
index 41d7ec1af..74f4a742e 100644
--- a/package.json
+++ b/package.json
@@ -76,6 +76,7 @@
     "iconv-lite": "^0.6.3",
     "istextorbinary": "^9.5.0",
     "jschardet": "^3.1.4",
+    "json5": "^2.2.3",
     "log-update": "^6.1.0",
     "minimatch": "^10.0.1",
     "picocolors": "^1.1.1",
diff --git a/repomix.config.json b/repomix.config.json
index d02dd0d32..b9ff43ce0 100644
--- a/repomix.config.json
+++ b/repomix.config.json
@@ -11,19 +11,19 @@
     "removeEmptyLines": false,
     "topFilesLength": 5,
     "showLineNumbers": false,
-    "includeEmptyDirectories": true
+    "includeEmptyDirectories": true,
   },
   "include": [],
   "ignore": {
     "useGitignore": true,
     "useDefaultPatterns": true,
     // ignore is specified in .repomixignore
-    "customPatterns": []
+    "customPatterns": [],
   },
   "security": {
-    "enableSecurityCheck": true
+    "enableSecurityCheck": true,
   },
   "tokenCount": {
-    "encoding": "o200k_base"
+    "encoding": "o200k_base",
   }
 }
diff --git a/src/config/configLoad.ts b/src/config/configLoad.ts
index 6c94a8b70..314884911 100644
--- a/src/config/configLoad.ts
+++ b/src/config/configLoad.ts
@@ -1,7 +1,7 @@
 import * as fs from 'node:fs/promises';
 import path from 'node:path';
+import JSON5 from 'json5';
 import pc from 'picocolors';
-import stripJsonComments from 'strip-json-comments';
 import { RepomixError, rethrowValidationErrorIfZodError } from '../shared/errorHandle.js';
 import { logger } from '../shared/logger.js';
 import {
@@ -70,12 +70,12 @@ export const loadFileConfig = async (rootDir: string, argConfigPath: string | nu
 const loadAndValidateConfig = async (filePath: string): Promise<RepomixConfigFile> => {
   try {
     const fileContent = await fs.readFile(filePath, 'utf-8');
-    const config = JSON.parse(stripJsonComments(fileContent));
+    const config = JSON5.parse(fileContent);
     return repomixConfigFileSchema.parse(config);
   } catch (error) {
     rethrowValidationErrorIfZodError(error, 'Invalid config schema');
     if (error instanceof SyntaxError) {
-      throw new RepomixError(`Invalid JSON in config file ${filePath}: ${error.message}`);
+      throw new RepomixError(`Invalid JSON5 in config file ${filePath}: ${error.message}`);
     }
     if (error instanceof Error) {
       throw new RepomixError(`Error loading config from ${filePath}: ${error.message}`);
diff --git a/tests/config/configLoad.test.ts b/tests/config/configLoad.test.ts
index e7db286e7..765d2f495 100644
--- a/tests/config/configLoad.test.ts
+++ b/tests/config/configLoad.test.ts
@@ -107,6 +107,37 @@ describe('configLoad', () => {
         ignore: { useGitignore: true },
       });
     });
+
+    test('should parse config file with JSON5 features', async () => {
+      const configWithJSON5Features = `{
+        // Output configuration
+        output: {
+          filePath: 'test-output.txt',
+          style: 'plain',
+        },
+        /* Ignore configuration */
+        ignore: {
+          useGitignore: true, // Use .gitignore file
+          customPatterns: [
+            '*.log',
+            '*.tmp',
+            '*.temp', // Trailing comma
+          ],
+        },
+      }`;
+
+      vi.mocked(fs.readFile).mockResolvedValue(configWithJSON5Features);
+      vi.mocked(fs.stat).mockResolvedValue({ isFile: () => true } as Stats);
+
+      const result = await loadFileConfig(process.cwd(), 'test-config.json');
+      expect(result).toEqual({
+        output: { filePath: 'test-output.txt', style: 'plain' },
+        ignore: {
+          useGitignore: true,
+          customPatterns: ['*.log', '*.tmp', '*.temp'],
+        },
+      });
+    });
   });
 
   describe('mergeConfigs', () => {