diff --git a/src/corelib/global/q20utility.h b/src/corelib/global/q20utility.h
index b24c81b924d..96d89db7341 100644
--- a/src/corelib/global/q20utility.h
+++ b/src/corelib/global/q20utility.h
@@ -118,6 +118,21 @@ constexpr bool in_range(T t) noexcept
 #endif // __cpp_lib_integer_comparison_functions
 } // namespace q20
 
+// like C++20 std::exchange (ie. constexpr, not yet noexcept)
+namespace q20 {
+#ifdef __cpp_lib_constexpr_algorithms
+using std::exchange;
+#else
+template <typename T, typename U = T>
+constexpr T exchange(T& obj, U&& newValue)
+{
+    T old = std::move(obj);
+    obj = std::forward<U>(newValue);
+    return old;
+}
+#endif
+}
+
 QT_END_NAMESPACE
 
 #endif /* Q20UTILITY_H */
diff --git a/src/corelib/tools/qscopedvaluerollback.h b/src/corelib/tools/qscopedvaluerollback.h
index bb24bfe2d1c..99da9e2cb22 100644
--- a/src/corelib/tools/qscopedvaluerollback.h
+++ b/src/corelib/tools/qscopedvaluerollback.h
@@ -6,6 +6,8 @@
 
 #include <QtCore/qglobal.h>
 
+#include <QtCore/q20utility.h>
+
 QT_BEGIN_NAMESPACE
 
 template <typename T>
@@ -20,9 +22,8 @@ public:
 
     Q_NODISCARD_CTOR
     explicit constexpr QScopedValueRollback(T &var, T value)
-        : varRef(var), oldValue(std::move(var)) // ### C++20: std::exchange(var, std::move(value))
+        : varRef(var), oldValue(q20::exchange(var, std::move(value)))
     {
-        var = std::move(value);
     }
 
     Q_DECL_CONSTEXPR_DTOR