diff --git a/runpod/cli/groups/config/functions.py b/runpod/cli/groups/config/functions.py
index ba6adffe..6b7c21bb 100644
--- a/runpod/cli/groups/config/functions.py
+++ b/runpod/cli/groups/config/functions.py
@@ -9,6 +9,7 @@
 from pathlib import Path
 
 import tomli as toml
+import tomlkit
 
 CREDENTIAL_FILE = os.path.expanduser("~/.runpod/config.toml")
 
@@ -30,16 +31,23 @@ def set_credentials(api_key: str, profile: str = "default", overwrite=False) ->
     os.makedirs(os.path.dirname(CREDENTIAL_FILE), exist_ok=True)
     Path(CREDENTIAL_FILE).touch(exist_ok=True)
 
+    with open(CREDENTIAL_FILE, "r", encoding="UTF-8") as cred_file:
+        try:
+            content = cred_file.read()
+            config = tomlkit.parse(content) if content.strip() else tomlkit.document()
+        except tomlkit.exceptions.ParseError as exc:
+            raise ValueError("~/.runpod/config.toml is not a valid TOML file.") from exc
+
     if not overwrite:
-        with open(CREDENTIAL_FILE, "rb") as cred_file:
-            if profile in toml.load(cred_file):
-                raise ValueError(
-                    "Profile already exists. Use `update_credentials` instead."
-                )
+        if profile in config:
+            raise ValueError(
+                "Profile already exists. Use `update_credentials` instead."
+            )
+
+    config[profile] = {"api_key": api_key}
 
     with open(CREDENTIAL_FILE, "w", encoding="UTF-8") as cred_file:
-        cred_file.write("[" + profile + "]\n")
-        cred_file.write('api_key = "' + api_key + '"\n')
+        tomlkit.dump(config, cred_file)
 
 
 def check_credentials(profile: str = "default"):
diff --git a/tests/test_cli/test_cli_groups/test_config_functions.py b/tests/test_cli/test_cli_groups/test_config_functions.py
index 14c8418a..8c29b8f8 100644
--- a/tests/test_cli/test_cli_groups/test_config_functions.py
+++ b/tests/test_cli/test_cli_groups/test_config_functions.py
@@ -14,19 +14,31 @@ class TestConfig(unittest.TestCase):
     def setUp(self) -> None:
         self.sample_credentials = "[default]\n" 'api_key = "RUNPOD_API_KEY"\n'
 
-    @patch("runpod.cli.groups.config.functions.toml.load")
-    @patch("builtins.open", new_callable=mock_open())
-    def test_set_credentials(self, mock_file, mock_toml_load):
+    @patch("runpod.cli.groups.config.functions.tomlkit.dump")
+    @patch("runpod.cli.groups.config.functions.tomlkit.document")
+    @patch("builtins.open", new_callable=mock_open, read_data="")
+    def test_set_credentials(self, mock_file, mock_document, mock_dump):
         """
         Tests the set_credentials function.
         """
-        mock_toml_load.return_value = ""
+        mock_document.side_effect = [{}, {"default": True}]
         functions.set_credentials("RUNPOD_API_KEY")
 
-        mock_file.assert_called_with(functions.CREDENTIAL_FILE, "w", encoding="UTF-8")
+        assert any(
+            call.args[0] == functions.CREDENTIAL_FILE
+            and call.args[1] == "r"
+            and call.kwargs.get("encoding") == "UTF-8"
+            for call in mock_file.call_args_list
+        )
+        assert any(
+            call.args[0] == functions.CREDENTIAL_FILE
+            and call.args[1] == "w"
+            and call.kwargs.get("encoding") == "UTF-8"
+            for call in mock_file.call_args_list
+        )
+        assert mock_dump.called
 
         with self.assertRaises(ValueError) as context:
-            mock_toml_load.return_value = {"default": True}
             functions.set_credentials("RUNPOD_API_KEY")
 
         self.assertEqual(