diff --git a/src/corelib/tools/quniquehandle_types.cpp b/src/corelib/tools/quniquehandle_types.cpp
index 59b9ebe179c..a46006ab6f3 100644
--- a/src/corelib/tools/quniquehandle_types.cpp
+++ b/src/corelib/tools/quniquehandle_types.cpp
@@ -19,12 +19,12 @@ namespace QtUniqueHandleTraits {
 
 #ifdef Q_OS_WIN
 
-bool InvalidHandleTraits::close(Type handle)
+bool InvalidHandleTraits::close(Type handle) noexcept
 {
     return ::CloseHandle(handle);
 }
 
-bool NullHandleTraits::close(Type handle)
+bool NullHandleTraits::close(Type handle) noexcept
 {
     return ::CloseHandle(handle);
 }
@@ -33,11 +33,13 @@ bool NullHandleTraits::close(Type handle)
 
 bool FileDescriptorHandleTraits::close(Type handle)
 {
+    // not noexcept because close() is a POSIX cancellation point
     return QT_CLOSE(handle) == 0;
 }
 
 bool FILEHandleTraits::close(Type handle)
 {
+    // not noexcept because fclose() is a POSIX cancellation point
     return ::fclose(handle);
 }
 
diff --git a/src/corelib/tools/quniquehandle_types_p.h b/src/corelib/tools/quniquehandle_types_p.h
index 01bcfd76bba..59dacb1cf09 100644
--- a/src/corelib/tools/quniquehandle_types_p.h
+++ b/src/corelib/tools/quniquehandle_types_p.h
@@ -33,14 +33,14 @@ struct InvalidHandleTraits
     {
         return Qt::HANDLE(-1); // AKA INVALID_HANDLE_VALUE
     }
-    Q_CORE_EXPORT static bool close(Type handle);
+    Q_CORE_EXPORT static bool close(Type handle) noexcept;
 };
 
 struct NullHandleTraits
 {
     using Type = Qt::HANDLE;
     static Type invalidValue() noexcept { return nullptr; }
-    Q_CORE_EXPORT static bool close(Type handle);
+    Q_CORE_EXPORT static bool close(Type handle) noexcept;
 };
 
 #endif