diff --git a/src/kicontheme.cpp b/src/kicontheme.cpp
--- a/src/kicontheme.cpp
+++ b/src/kicontheme.cpp
@@ -69,20 +69,6 @@
 }
 Q_COREAPP_STARTUP_FUNCTION(initRCCIconTheme)
 
-// Set the icon theme fallback to breeze
-// Most of our apps use "lots" of icons that most of the times
-// are only available with breeze, we still honour the user icon
-// theme but if the icon is not found there, we go to breeze
-// since it's almost sure it'll be there
-static void setBreezeFallback()
-{
-#if QT_VERSION >= QT_VERSION_CHECK(5, 12, 0)
-    QIcon::setFallbackThemeName(QStringLiteral("breeze"));
-#endif
-}
-
-Q_COREAPP_STARTUP_FUNCTION(setBreezeFallback)
-
 class Q_DECL_HIDDEN KIconTheme::KIconThemePrivate
 {
 public:
@@ -107,6 +93,7 @@
 Q_GLOBAL_STATIC(QString, _theme)
 Q_GLOBAL_STATIC(QStringList, _theme_list)
 
+
 /**
  * A subdirectory in an icon theme.
  */
@@ -264,6 +251,23 @@
 KIconTheme::KIconTheme(const QString &name, const QString &appName, const QString &basePathHint)
     : d(new KIconThemePrivate)
 {
+// Set the icon theme fallback to breeze
+// Most of our apps use "lots" of icons that most of the times
+// are only available with breeze, we still honour the user icon
+// theme but if the icon is not found there, we go to breeze
+// since it's almost sure it'll be there.
+// Doing this as Q_COREAPP_STARTUP_FUNCTION is too soon as
+// at that point QPlatformTheme is not instantiated yet and
+// breaks the internal status of QIconLoader
+// see https://bugreports.qt.io/browse/QTBUG-74252
+#if QT_VERSION >= QT_VERSION_CHECK(5, 12, 0)
+    static bool s_fallbackThemeInitialized;
+    if (!s_fallbackThemeInitialized) {
+        QIcon::setFallbackThemeName(QStringLiteral("breeze"));
+        s_fallbackThemeInitialized = true;
+    }
+#endif
+
     d->mInternalName = name;
 
     QStringList themeDirs;