diff --git a/src/corelib/kernel/qmath.h b/src/corelib/kernel/qmath.h
index 5e8d4fc2767..2171a4ed93e 100644
--- a/src/corelib/kernel/qmath.h
+++ b/src/corelib/kernel/qmath.h
@@ -371,6 +371,8 @@ constexpr inline quint64 qConstexprNextPowerOfTwo(qint64 v)
 constexpr inline quint32 qNextPowerOfTwo(quint32 v)
 {
 #if defined(__cpp_lib_int_pow2) && __cpp_lib_int_pow2 >= 202002L
+    if (static_cast<qint32>(v) < 0)
+        return 0; // std::bit_ceil() is undefined for values that would overflow, but we document them to be 0
     return std::bit_ceil(v + 1);
 #elif defined(QT_HAS_BUILTIN_CLZ)
     if (v == 0)
@@ -384,6 +386,8 @@ constexpr inline quint32 qNextPowerOfTwo(quint32 v)
 constexpr inline quint64 qNextPowerOfTwo(quint64 v)
 {
 #if defined(__cpp_lib_int_pow2) && __cpp_lib_int_pow2 >= 202002L
+    if (static_cast<qint64>(v) < 0)
+        return 0; // std::bit_ceil() is undefined for values that would overflow, but we document them to be 0
     return std::bit_ceil(v + 1);
 #elif defined(QT_HAS_BUILTIN_CLZLL)
     if (v == 0)