diff --git a/src/plugins/clangcodemodel/clangtextmark.cpp b/src/plugins/clangcodemodel/clangtextmark.cpp
index bbd3074c1a4..c3ead0aa4c1 100644
--- a/src/plugins/clangcodemodel/clangtextmark.cpp
+++ b/src/plugins/clangcodemodel/clangtextmark.cpp
@@ -312,7 +312,7 @@ Task createTask(const ClangDiagnostic &diagnostic)
 ClangdTextMark::ClangdTextMark(const FilePath &filePath,
                                const Diagnostic &diagnostic,
                                bool isProjectFile,
-                               Client *client)
+                               ClangdClient *client)
     : TextEditor::TextMark(filePath, int(diagnostic.range().start().line() + 1), client->id())
     , m_lspDiagnostic(diagnostic)
     , m_diagnostic(convertDiagnostic(ClangdDiagnostic(diagnostic), filePath))
@@ -330,7 +330,7 @@ ClangdTextMark::ClangdTextMark(const FilePath &filePath,
         setLineAnnotation(diagnostic.message());
         setColor(isError ? Theme::CodeModel_Error_TextMarkColor
                          : Theme::CodeModel_Warning_TextMarkColor);
-        qobject_cast<ClangdClient *>(client)->addTask(createTask(m_diagnostic));
+        client->addTask(createTask(m_diagnostic));
     }
 
     // Copy to clipboard action
diff --git a/src/plugins/clangcodemodel/clangtextmark.h b/src/plugins/clangcodemodel/clangtextmark.h
index 0db460ed62a..39f30bc36cf 100644
--- a/src/plugins/clangcodemodel/clangtextmark.h
+++ b/src/plugins/clangcodemodel/clangtextmark.h
@@ -40,6 +40,8 @@ namespace LanguageClient { class Client; }
 namespace ClangCodeModel {
 namespace Internal {
 
+class ClangdClient;
+
 class ClangdTextMark : public TextEditor::TextMark
 {
     Q_DECLARE_TR_FUNCTIONS(ClangdTextMark)
@@ -47,7 +49,7 @@ public:
     ClangdTextMark(const ::Utils::FilePath &filePath,
                    const LanguageServerProtocol::Diagnostic &diagnostic,
                    bool isProjectFile,
-                   LanguageClient::Client *client);
+                   ClangdClient *client);
 
 private:
     bool addToolTipContent(QLayout *target) const override;