diff --git a/src/plugins/python/pythonlanguageclient.cpp b/src/plugins/python/pythonlanguageclient.cpp
index b129a069049..2a4ea8c7d97 100644
--- a/src/plugins/python/pythonlanguageclient.cpp
+++ b/src/plugins/python/pythonlanguageclient.cpp
@@ -181,9 +181,9 @@ PyLSClient *clientForPython(const FilePath &python)
     return client;
 }
 
-PyLSClient::PyLSClient(BaseClientInterface *interface)
+PyLSClient::PyLSClient(PyLSInterface *interface)
     : Client(interface)
-    , m_extraCompilerOutputDir(static_cast<PyLSInterface *>(interface)->m_extraPythonPath.path())
+    , m_extraCompilerOutputDir(interface->m_extraPythonPath.path())
 {
     connect(this, &Client::initialized, this, &PyLSClient::updateConfiguration);
     connect(PythonSettings::instance(), &PythonSettings::pylsConfigurationChanged,
diff --git a/src/plugins/python/pythonlanguageclient.h b/src/plugins/python/pythonlanguageclient.h
index ed0c16b5893..c58103c5fbf 100644
--- a/src/plugins/python/pythonlanguageclient.h
+++ b/src/plugins/python/pythonlanguageclient.h
@@ -40,12 +40,13 @@ namespace Internal {
 
 class PySideUicExtraCompiler;
 class PythonLanguageServerState;
+class PyLSInterface;
 
 class PyLSClient : public LanguageClient::Client
 {
     Q_OBJECT
 public:
-    explicit PyLSClient(LanguageClient::BaseClientInterface *interface);
+    explicit PyLSClient(PyLSInterface *interface);
     ~PyLSClient();
 
     void openDocument(TextEditor::TextDocument *document) override;