--- a/widget/headless/HeadlessWidget.h
+++ b/widget/headless/HeadlessWidget.h
@@ -17,17 +17,17 @@
 #define MOZ_HEADLESS_MOUSE_MOVE 3 // GDK_MOTION_NOTIFY
 #define MOZ_HEADLESS_MOUSE_DOWN 4 // GDK_BUTTON_PRESS
 #define MOZ_HEADLESS_MOUSE_UP   7 // GDK_BUTTON_RELEASE
 #define MOZ_HEADLESS_SCROLL_MULTIPLIER 3
 #elif defined(XP_WIN)
 #define MOZ_HEADLESS_MOUSE_MOVE 1 // MOUSEEVENTF_MOVE
 #define MOZ_HEADLESS_MOUSE_DOWN 2 // MOUSEEVENTF_LEFTDOWN
 #define MOZ_HEADLESS_MOUSE_UP   4 // MOUSEEVENTF_LEFTUP
-#define MOZ_HEADLESS_SCROLL_MULTIPLIER 1
+#define MOZ_HEADLESS_SCROLL_MULTIPLIER .025 // default scroll lines (3) / WHEEL_DELTA (120)
 #elif defined(XP_MACOSX)
 #define MOZ_HEADLESS_MOUSE_MOVE 5 // NSMouseMoved
 #define MOZ_HEADLESS_MOUSE_DOWN 1 // NSLeftMouseDown
 #define MOZ_HEADLESS_MOUSE_UP   2 // NSLeftMouseUp
 #define MOZ_HEADLESS_SCROLL_MULTIPLIER 1
 #elif defined(ANDROID)
 #define MOZ_HEADLESS_MOUSE_MOVE 7 // ACTION_HOVER_MOVE
 #define MOZ_HEADLESS_MOUSE_DOWN 5 // ACTION_POINTER_DOWN