diff --git a/pdm.lock b/pdm.lock
index 5399112b3..4445fd2be 100644
--- a/pdm.lock
+++ b/pdm.lock
@@ -5,7 +5,7 @@
 groups = ["default", "dev"]
 strategy = ["inherit_metadata"]
 lock_version = "4.5.0"
-content_hash = "sha256:8dcb899b717280109d70077a4cc3195bfd2a89406e885b8baca012cb35deeae8"
+content_hash = "sha256:a61b1a29b26191b1402ee74c129493c29b9519851951940e4e38c0730299ac6f"
 
 [[metadata.targets]]
 requires_python = "~=3.9"
@@ -727,7 +727,7 @@ name = "ruamel-yaml"
 version = "0.18.10"
 requires_python = ">=3.7"
 summary = "ruamel.yaml is a YAML parser/emitter that supports roundtrip preservation of comments, seq/map flow style, and map key order"
-groups = ["default", "dev"]
+groups = ["default"]
 dependencies = [
     "ruamel-yaml-clib>=0.2.7; platform_python_implementation == \"CPython\" and python_version < \"3.13\"",
 ]
@@ -741,7 +741,7 @@ name = "ruamel-yaml-clib"
 version = "0.2.12"
 requires_python = ">=3.9"
 summary = "C version of reader, parser and emitter for ruamel.yaml derived from libyaml"
-groups = ["default", "dev"]
+groups = ["default"]
 marker = "platform_python_implementation == \"CPython\" and python_version < \"3.13\""
 files = [
     {file = "ruamel.yaml.clib-0.2.12-cp310-cp310-macosx_13_0_arm64.whl", hash = "sha256:11f891336688faf5156a36293a9c362bdc7c88f03a8a027c2c1d8e0bcde998e5"},
@@ -792,20 +792,6 @@ files = [
     {file = "ruamel.yaml.clib-0.2.12.tar.gz", hash = "sha256:6c8fbb13ec503f99a91901ab46e0b07ae7941cd527393187039aec586fdfd36f"},
 ]
 
-[[package]]
-name = "ruamel-yaml-string"
-version = "0.1.1"
-requires_python = ">=3"
-summary = "add dump_to_string/dumps method that returns YAML document as string"
-groups = ["dev"]
-dependencies = [
-    "ruamel-yaml>=0.17.17",
-]
-files = [
-    {file = "ruamel.yaml.string-0.1.1-py3-none-any.whl", hash = "sha256:eb146bcb42b116216638034a434e9cf3ae2a5d3933aa37183a9854b5f3ff42de"},
-    {file = "ruamel.yaml.string-0.1.1.tar.gz", hash = "sha256:7a7aedcc055d45c004d38b756f58474ebefb106851f4ce56ce58415709784350"},
-]
-
 [[package]]
 name = "ruff"
 version = "0.9.10"
diff --git a/pyproject.toml b/pyproject.toml
index ffacf7b8b..fc98d0def 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -95,7 +95,6 @@ dev = [
     "types-PyYAML<7.0.0,>=6.0.3",
     "types-certifi<2021.10.9,>=2020.0.0",
     "types-python-dateutil<3.0.0,>=2.0.0",
-    "ruamel-yaml-string>=0.1.1",
     "syrupy>=4",
 ]
 
diff --git a/tests/test_config.py b/tests/test_config.py
index c24766f9b..be2e8bf59 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -1,12 +1,22 @@
 import json
 import os
+from io import StringIO
 from pathlib import Path
+from typing import Any
 
 import pytest
-from ruamel.yaml import YAML
+from ruamel.yaml import YAML as _YAML
 
 from openapi_python_client.config import ConfigFile
 
+
+class YAML(_YAML):
+    def dump_to_string(self, data: Any, **kwargs: Any) -> str:
+        stream = StringIO()
+        self.dump(data=data, stream=stream, **kwargs)
+        return stream.getvalue()
+
+
 yaml = YAML(typ=["safe", "string"])