Index: source/blender/editors/mask/mask_edit.c
===================================================================
--- source/blender/editors/mask/mask_edit.c	(revision 49813)
+++ source/blender/editors/mask/mask_edit.c	(working copy)
@@ -444,7 +444,7 @@
 
 	/* geometry */
 	WM_keymap_add_item(keymap, "MASK_OT_add_vertex_slide", LEFTMOUSE, KM_PRESS, KM_CTRL, 0);
-	WM_keymap_add_item(keymap, "MASK_OT_add_feather_vertex_slide", LEFTMOUSE, KM_PRESS, KM_SHIFT, 0);
+	WM_keymap_add_item(keymap, "MASK_OT_add_feather_vertex_slide", LEFTMOUSE, KM_PRESS, KM_ALT, 0);
 	WM_keymap_add_item(keymap, "MASK_OT_delete", XKEY, KM_PRESS, 0, 0);
 	WM_keymap_add_item(keymap, "MASK_OT_delete", DELKEY, KM_PRESS, 0, 0);