diff --git a/src/gui/image/qfonticonengine.cpp b/src/gui/image/qfonticonengine.cpp
index e8e76271d19..e98fa1bffdd 100644
--- a/src/gui/image/qfonticonengine.cpp
+++ b/src/gui/image/qfonticonengine.cpp
@@ -25,6 +25,8 @@ QFontIconEngine::QFontIconEngine(const QString &iconName, const QFont &font)
     : m_iconName(iconName)
     , m_iconFont(font)
 {
+    Q_ASSERT_X(font.styleStrategy() & QFont::NoFontMerging, "QFontIconEngine",
+                "Icon fonts must not use font merging");
 }
 
 QFontIconEngine::~QFontIconEngine() = default;
diff --git a/src/plugins/platforms/android/qandroidplatformiconengine.cpp b/src/plugins/platforms/android/qandroidplatformiconengine.cpp
index 3d33d747455..bab6eeb9d4a 100644
--- a/src/plugins/platforms/android/qandroidplatformiconengine.cpp
+++ b/src/plugins/platforms/android/qandroidplatformiconengine.cpp
@@ -249,7 +249,9 @@ static QFont selectFont()
     // last resort - use any Material Icons
     if (fontFamily.isEmpty())
         fontFamily = u"Material Icons"_s;
-    return QFont(fontFamily);
+    QFont font(fontFamily);
+    font.setStyleStrategy(QFont::NoFontMerging);
+    return font;
 }
 
 } // namespace FontProvider
diff --git a/src/plugins/platforms/windows/qwindowsiconengine.cpp b/src/plugins/platforms/windows/qwindowsiconengine.cpp
index 272b56be836..71103183183 100644
--- a/src/plugins/platforms/windows/qwindowsiconengine.cpp
+++ b/src/plugins/platforms/windows/qwindowsiconengine.cpp
@@ -286,16 +286,18 @@ static QString getGlyphs(QStringView iconName)
 }
 
 namespace {
-static auto iconFontFamily()
+static auto iconFont()
 {
     static const bool isWindows11 = QOperatingSystemVersion::current() >= QOperatingSystemVersion::Windows11;
-    return isWindows11 ? u"Segoe Fluent Icons"_s
-                       : u"Segoe MDL2 Assets"_s;
+    QFont font(isWindows11 ? u"Segoe Fluent Icons"_s
+                           : u"Segoe MDL2 Assets"_s);
+    font.setStyleStrategy(QFont::NoFontMerging);
+    return font;
 }
 }
 
 QWindowsIconEngine::QWindowsIconEngine(const QString &iconName)
-    : QFontIconEngine(iconName, iconFontFamily())
+    : QFontIconEngine(iconName, iconFont())
     , m_glyphs(getGlyphs(iconName))
 {
 }