diff --git a/kcms/fonts/package/contents/ui/main.qml b/kcms/fonts/package/contents/ui/main.qml
--- a/kcms/fonts/package/contents/ui/main.qml
+++ b/kcms/fonts/package/contents/ui/main.qml
@@ -180,6 +180,7 @@
         QtDialogs.FontDialog {
             id: fontDialog
             title: "Choose a font"
+            modality: Qt.WindowModal
             property string currentCategory
             property bool adjustAllFonts: false
             onAccepted: {