diff -up firefox-60.5.0/widget/gtk/nsWindow.cpp.1196777 firefox-60.5.0/widget/gtk/nsWindow.cpp
--- firefox-60.5.0/widget/gtk/nsWindow.cpp.1196777	2019-01-22 11:41:58.630469400 +0100
+++ firefox-60.5.0/widget/gtk/nsWindow.cpp	2019-01-22 11:42:50.134227448 +0100
@@ -152,7 +152,8 @@ const gint kEvents =
 #if GTK_CHECK_VERSION(3, 4, 0)
     GDK_SMOOTH_SCROLL_MASK | GDK_TOUCH_MASK |
 #endif
-    GDK_SCROLL_MASK | GDK_POINTER_MOTION_MASK | GDK_PROPERTY_CHANGE_MASK;
+    GDK_SCROLL_MASK | GDK_POINTER_MOTION_MASK | GDK_PROPERTY_CHANGE_MASK |
+    GDK_FOCUS_CHANGE_MASK;
 
 /* utility functions */
 static bool is_mouse_in_window(GdkWindow *aWindow, gdouble aMouseX,