diff --git a/src/utils/checker.h b/src/utils/checker.h
deleted file mode 100644
index ef7ec2db1..000000000
--- a/src/utils/checker.h
+++ /dev/null
@@ -1,126 +0,0 @@
-/****************************************************************************
-** SPDX-FileCopyrightText: 2001-2007 Klarälvdalens Datakonsult AB. All rights reserved.
-**
-** This file is part of the KD Tools library.
-**
-** SPDX-License-Identifier: GPL-2.0-only
-**
-**********************************************************************/
-
-#pragma once
-
-#include "kdtoolsglobal.h"
-
-#include <cstdlib>
-
-/**
-   Usage:
-
-   \code
-   class Foo ... {
-      KDAB_MAKE_CHECKABLE( Foo )
-   public:
-      // ...
-   };
-
-   Foo::Foo() {
-      KDAB_CHECK_CTOR;
-      // ...
-   }
-
-   Foo::~Foo() {
-      KDAB_CHECK_DTOR;
-      // ...
-   }
-
-   KDAB_DEFINE_CHECKS( Foo ) {
-      Q_ASSERT( something );
-      Q_ASSERT( another thing );
-   }
-
-   void Foo::setBar( int bar ) {
-      KDAB_CHECK_THIS; // include as first line in every method
-
-      // ...
-   }
-
-   int Foo::bar() const {
-      KDAB_CHECK_THIS;
-
-      // ...
-   }
-   \endcode
-*/
-class __KDAB__CheckerImplBase
-{
-public:
-    virtual ~__KDAB__CheckerImplBase()
-    {
-    }
-    virtual void checkInvariants() const = 0;
-};
-
-template<typename T_Class>
-class __KDAB__CheckerImpl : public __KDAB__CheckerImplBase
-{
-    KDAB_DISABLE_COPY(__KDAB__CheckerImpl);
-    const T_Class *const p;
-
-public:
-    __KDAB__CheckerImpl(const T_Class *t)
-        : __KDAB__CheckerImplBase()
-        , p(t)
-    {
-    }
-    void checkInvariants() const
-    {
-        try {
-            p->__KDAB_Checker__checkInvariants__();
-        } catch (...) {
-            std::abort();
-        }
-    }
-};
-
-template<bool check_in_ctor, bool check_in_dtor>
-class __KDAB__Checker
-{
-    KDAB_DISABLE_COPY(__KDAB__Checker);
-    const __KDAB__CheckerImplBase *const checker;
-
-public:
-    template<typename T_Class>
-    __KDAB__Checker(const T_Class *t)
-        : checker(new __KDAB__CheckerImpl<T_Class>(t))
-    {
-        if (check_in_ctor) {
-            checker->checkInvariants();
-        }
-    }
-    ~__KDAB__Checker()
-    {
-        if (check_in_dtor) {
-            checker->checkInvariants();
-        }
-        delete checker;
-    }
-};
-
-#define KDAB_MAKE_CHECKABLE(Class)                                                                                                                             \
-private:                                                                                                                                                       \
-    void __KDAB_Checker__checkInvariants__() const;                                                                                                            \
-    friend class __KDAB__CheckerImpl<Class>;
-
-#define KDAB_DEFINE_CHECKS(Class) void Class::__KDAB_Checker__checkInvariants__() const
-
-#ifndef NDEBUG
-#define __KDAB_CHECK_HELPER__(ctor, dtor) const __KDAB__Checker<ctor, dtor> __checker_uglified__(this)
-#else
-#define __KDAB_CHECK_HELPER__(ctor, dtor)                                                                                                                      \
-    do {                                                                                                                                                       \
-    } while (0)
-#endif
-
-#define KDAB_CHECK_THIS __KDAB_CHECK_HELPER__(true, true)
-#define KDAB_CHECK_CTOR __KDAB_CHECK_HELPER__(false, true)
-#define KDAB_CHECK_DTOR __KDAB_CHECK_HELPER__(true, false)