diff --git a/src/GUI/QtFileDialog.cxx b/src/GUI/QtFileDialog.cxx
index effae6650..480b2566a 100644
--- a/src/GUI/QtFileDialog.cxx
+++ b/src/GUI/QtFileDialog.cxx
@@ -40,9 +40,12 @@ void QtFileDialog::exec()
     int fakeargc = 1;
     static char fakeargv0[] = "fgfs";
     static char * fakeargv[2] = {fakeargv0, 0};
-    // This does nothing if it has already been run, so the fake argc/argv
-    // are only used if run without launcher
-    flightgear::initApp(fakeargc, fakeargv);
+    // This does nothing if it has already been run, so the fake argc/argv are
+    // only used if run without launcher. Don't attempt to initialize the
+    // QSettings, because this would require FGGlobals to be initialized (for
+    // globals->get_fg_home()), which would prevent using this function at
+    // early startup.
+    flightgear::initApp(fakeargc, fakeargv, false /* doInitQSettings */);
     
     // concatenate filter patterns, as Qt uses a single string
     std::string filter="";
diff --git a/src/GUI/QtLauncher.cxx b/src/GUI/QtLauncher.cxx
index 8a1fdacf9..a255a7632 100644
--- a/src/GUI/QtLauncher.cxx
+++ b/src/GUI/QtLauncher.cxx
@@ -83,6 +83,7 @@
 
 using namespace flightgear;
 using namespace simgear::pkg;
+using std::string;
 
 const int MAX_RECENT_AIRCRAFT = 20;
 const int DEFAULT_MP_PORT = 5000;
@@ -505,7 +506,9 @@ static void initQtResources()
 namespace flightgear
 {
 
-void initApp(int& argc, char** argv)
+// Only requires FGGlobals to be initialized if 'doInitQSettings' is true.
+// Safe to call several times.
+void initApp(int& argc, char** argv, bool doInitQSettings)
 {
     static bool qtInitDone = false;
     static int s_argc;
@@ -525,22 +528,45 @@ void initApp(int& argc, char** argv)
         app->setApplicationName("FlightGear");
         app->setOrganizationDomain("flightgear.org");
 
-        QSettings::setDefaultFormat(QSettings::IniFormat);
-        QSettings::setPath(QSettings::IniFormat, QSettings::UserScope,
-                           QString::fromStdString(globals->get_fg_home().utf8Str()));
-
         // reset numeric / collation locales as described at:
         // http://doc.qt.io/qt-5/qcoreapplication.html#details
         ::setlocale(LC_NUMERIC, "C");
         ::setlocale(LC_COLLATE, "C");
-
-        Qt::KeyboardModifiers mods = app->queryKeyboardModifiers();
-        if (mods & (Qt::AltModifier | Qt::ShiftModifier)) {
-            qWarning() << "Alt/shift pressed during launch";
-            QSettings settings;
-            settings.setValue("fg-root", "!ask");
-        }
     }
+
+    if (doInitQSettings) {
+        initQSettings();
+    }
+}
+
+// Requires FGGlobals to be initialized. Safe to call several times.
+void initQSettings()
+{
+    static bool qSettingsInitDone = false;
+
+    if (!qSettingsInitDone) {
+        qSettingsInitDone = true;
+        string fgHome = globals->get_fg_home().utf8Str();
+
+        QSettings::setDefaultFormat(QSettings::IniFormat);
+        QSettings::setPath(QSettings::IniFormat, QSettings::UserScope,
+                           QString::fromStdString(fgHome));
+    }
+}
+
+bool checkKeyboardModifiersForSettingFGRoot()
+{
+    initQSettings();
+
+    Qt::KeyboardModifiers mods = qApp->queryKeyboardModifiers();
+    if (mods & (Qt::AltModifier | Qt::ShiftModifier)) {
+        qWarning() << "Alt/shift pressed during launch";
+        QSettings settings;
+        settings.setValue("fg-root", "!ask");
+        return true;
+    }
+
+    return false;
 }
 
 bool runLauncherDialog()
diff --git a/src/GUI/QtLauncher.hxx b/src/GUI/QtLauncher.hxx
index bc9d844df..a24d89a1a 100644
--- a/src/GUI/QtLauncher.hxx
+++ b/src/GUI/QtLauncher.hxx
@@ -23,7 +23,15 @@
 
 namespace flightgear
 {
-  void initApp(int& argc, char** argv);
+  // Only requires FGGlobals to be initialized if 'doInitQSettings' is true.
+  // Safe to call several times.
+  void initApp(int& argc, char** argv, bool doInitQSettings = true);
+  // Requires FGGlobals to be initialized. Safe to call several times.
+  void initQSettings();
+
+  // Set 'fg-root' in QSettings to the special value "!ask" if either Alt or
+  // Shift is pressed. Return true in this case, false otherwise.
+  bool checkKeyboardModifiersForSettingFGRoot();
 
   bool runLauncherDialog();
 
diff --git a/src/GUI/QtMessageBox.cxx b/src/GUI/QtMessageBox.cxx
index 430bc34d0..d8aa4a609 100644
--- a/src/GUI/QtMessageBox.cxx
+++ b/src/GUI/QtMessageBox.cxx
@@ -34,9 +34,12 @@ QtMessageBox(const std::string& caption,
     int fakeargc = 1;
     static char fakeargv0[] = "fgfs";
     static char * fakeargv[2] = {fakeargv0, 0};
-    // This does nothing if it has already been run, so the fake argc/argv
-    // are only used if an error box is triggered in early startup
-    flightgear::initApp(fakeargc, fakeargv);
+    // This does nothing if it has already been run, so the fake argc/argv are
+    // only used if an error box is triggered in early startup. Don't attempt
+    // to initialize the QSettings, because this would require FGGlobals to be
+    // initialized (for globals->get_fg_home()), which would prevent using
+    // this function at early startup.
+    flightgear::initApp(fakeargc, fakeargv, false /* doInitQSettings */);
     QMessageBox msgBox;
     msgBox.setWindowTitle(QString::fromStdString(caption));
     msgBox.setText(QString::fromStdString(msg));
diff --git a/src/Main/main.cxx b/src/Main/main.cxx
index bed7e2954..2e7997e81 100644
--- a/src/Main/main.cxx
+++ b/src/Main/main.cxx
@@ -495,6 +495,8 @@ int fgMainInit( int argc, char **argv )
 #if defined(HAVE_QT)
     if (showLauncher) {
         flightgear::initApp(argc, argv);
+        flightgear::checkKeyboardModifiersForSettingFGRoot();
+
         if (!flightgear::runLauncherDialog()) {
             return EXIT_SUCCESS;
         }