diff --git a/src/corelib/io/qprocess.cpp b/src/corelib/io/qprocess.cpp
index 41a7fffd8b..7f3cc7bd89 100644
--- a/src/corelib/io/qprocess.cpp
+++ b/src/corelib/io/qprocess.cpp
@@ -1588,15 +1588,6 @@ std::function<void(void)> QProcess::childProcessModifier() const
     "async-signal-safe" is advised). Most of the Qt API is unsafe inside this
     callback, including qDebug(), and may lead to deadlocks.
 
-    \note On some systems (notably, Linux), QProcess will use \c{vfork()}
-    semantics to start the child process, so this function must obey even
-    stricter constraints. First, because it is still sharing memory with the
-    parent process, it must not write to any non-local variable and must obey
-    proper ordering semantics when reading from them, to avoid data races.
-    Second, even more library functions may misbehave; therefore, this function
-    should only make use of low-level system calls, such as \c{read()},
-    \c{write()}, \c{setsid()}, \c{nice()}, and similar.
-
     \sa childProcessModifier()
 */
 void QProcess::setChildProcessModifier(const std::function<void(void)> &modifier)
diff --git a/src/corelib/io/qprocess_unix.cpp b/src/corelib/io/qprocess_unix.cpp
index 741cabe6fe..a5e52fb793 100644
--- a/src/corelib/io/qprocess_unix.cpp
+++ b/src/corelib/io/qprocess_unix.cpp
@@ -471,6 +471,8 @@ void QProcessPrivate::startProcess()
 #if defined(Q_OS_LINUX) && !QT_CONFIG(forkfd_pidfd)
     ffdflags |= FFD_USE_FORK;
 #endif
+    if (unixExtras && unixExtras->childProcessModifier)
+        ffdflags |= FFD_USE_FORK;
 
     pid_t childPid;
     forkfd = ::vforkfd(ffdflags , &childPid, execChild2, &execChild1);