diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index cce9d1c..5660725 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "1.7.0"
+  ".": "1.7.1"
 }
\ No newline at end of file
diff --git a/.stats.yml b/.stats.yml
index 603f57a..25ece8f 100644
--- a/.stats.yml
+++ b/.stats.yml
@@ -1,4 +1,4 @@
 configured_endpoints: 21
-openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/cas-parser%2Fcas-parser-d9763d006969b49a1473851069fdfa429eb13133b64103a62963bb70ddb22305.yml
-openapi_spec_hash: 6aee689b7a759b12c85c088c15e29bc0
+openapi_spec_url: https://storage.googleapis.com/stainless-sdk-openapi-specs/cas-parser%2Fcas-parser-d868ff00b7b07f6b6802b00f22fad531a91a76bb219a634f3f90fe488bd499ba.yml
+openapi_spec_hash: 20e9f2fc31feee78878cdf56e46dab60
 config_hash: 5509bb7a961ae2e79114b24c381606d4
diff --git a/CHANGELOG.md b/CHANGELOG.md
index af49a3a..0048f09 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 1.7.1 (2026-04-08)
+
+Full Changelog: [v1.7.0...v1.7.1](https://github.com/CASParser/cas-parser-python/compare/v1.7.0...v1.7.1)
+
+### Bug Fixes
+
+* **client:** preserve hardcoded query params when merging with user params ([3e5eea1](https://github.com/CASParser/cas-parser-python/commit/3e5eea1e92928bd98243022c607f6f15afa24d52))
+
 ## 1.7.0 (2026-03-27)
 
 Full Changelog: [v1.6.3...v1.7.0](https://github.com/CASParser/cas-parser-python/compare/v1.6.3...v1.7.0)
diff --git a/pyproject.toml b/pyproject.toml
index 724085d..ffa8d10 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "cas-parser-python"
-version = "1.7.0"
+version = "1.7.1"
 description = "The official Python library for the cas-parser API"
 dynamic = ["readme"]
 license = "Apache-2.0"
diff --git a/src/cas_parser/_base_client.py b/src/cas_parser/_base_client.py
index 5b130cf..33ae5fa 100644
--- a/src/cas_parser/_base_client.py
+++ b/src/cas_parser/_base_client.py
@@ -558,6 +558,10 @@ def _build_request(
                 files = cast(HttpxRequestFiles, ForceMultipartDict())
 
         prepared_url = self._prepare_url(options.url)
+        # preserve hard-coded query params from the url
+        if params and prepared_url.query:
+            params = {**dict(prepared_url.params.items()), **params}
+            prepared_url = prepared_url.copy_with(raw_path=prepared_url.raw_path.split(b"?", 1)[0])
         if "_" in prepared_url.host:
             # work around https://github.com/encode/httpx/discussions/2880
             kwargs["extensions"] = {"sni_hostname": prepared_url.host.replace("_", "-")}
diff --git a/src/cas_parser/_version.py b/src/cas_parser/_version.py
index e314464..816fce9 100644
--- a/src/cas_parser/_version.py
+++ b/src/cas_parser/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "cas_parser"
-__version__ = "1.7.0"  # x-release-please-version
+__version__ = "1.7.1"  # x-release-please-version
diff --git a/tests/test_client.py b/tests/test_client.py
index 9e2377f..dd96b67 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -429,6 +429,30 @@ def test_default_query_option(self) -> None:
 
         client.close()
 
+    def test_hardcoded_query_params_in_url(self, client: CasParser) -> None:
+        request = client._build_request(FinalRequestOptions(method="get", url="/foo?beta=true"))
+        url = httpx.URL(request.url)
+        assert dict(url.params) == {"beta": "true"}
+
+        request = client._build_request(
+            FinalRequestOptions(
+                method="get",
+                url="/foo?beta=true",
+                params={"limit": "10", "page": "abc"},
+            )
+        )
+        url = httpx.URL(request.url)
+        assert dict(url.params) == {"beta": "true", "limit": "10", "page": "abc"}
+
+        request = client._build_request(
+            FinalRequestOptions(
+                method="get",
+                url="/files/a%2Fb?beta=true",
+                params={"limit": "10"},
+            )
+        )
+        assert request.url.raw_path == b"/files/a%2Fb?beta=true&limit=10"
+
     def test_request_extra_json(self, client: CasParser) -> None:
         request = client._build_request(
             FinalRequestOptions(
@@ -1320,6 +1344,30 @@ async def test_default_query_option(self) -> None:
 
         await client.close()
 
+    async def test_hardcoded_query_params_in_url(self, async_client: AsyncCasParser) -> None:
+        request = async_client._build_request(FinalRequestOptions(method="get", url="/foo?beta=true"))
+        url = httpx.URL(request.url)
+        assert dict(url.params) == {"beta": "true"}
+
+        request = async_client._build_request(
+            FinalRequestOptions(
+                method="get",
+                url="/foo?beta=true",
+                params={"limit": "10", "page": "abc"},
+            )
+        )
+        url = httpx.URL(request.url)
+        assert dict(url.params) == {"beta": "true", "limit": "10", "page": "abc"}
+
+        request = async_client._build_request(
+            FinalRequestOptions(
+                method="get",
+                url="/files/a%2Fb?beta=true",
+                params={"limit": "10"},
+            )
+        )
+        assert request.url.raw_path == b"/files/a%2Fb?beta=true&limit=10"
+
     def test_request_extra_json(self, client: CasParser) -> None:
         request = client._build_request(
             FinalRequestOptions(