diff --git a/frontend/device/input.lua b/frontend/device/input.lua
index 0a46ceca0..fbf27b3cf 100644
--- a/frontend/device/input.lua
+++ b/frontend/device/input.lua
@@ -155,10 +155,15 @@ end
 -- catalogue of predefined hooks:
 function Input:adjustTouchSwitchXY(ev)
     if ev.type == EV_ABS then
-        if ev.code == ABS_X then ev.code = ABS_Y end
-        if ev.code == ABS_Y then ev.code = ABS_X end
-        if ev.code == ABS_MT_POSITION_X then ev.code = ABS_MT_POSITION_Y end
-        if ev.code == ABS_MT_POSITION_Y then ev.code = ABS_MT_POSITION_X end
+        if ev.code == ABS_X then
+            ev.code = ABS_Y
+        elseif ev.code == ABS_Y then
+            ev.code = ABS_X
+        elseif ev.code == ABS_MT_POSITION_X then
+            ev.code = ABS_MT_POSITION_Y
+        elseif ev.code == ABS_MT_POSITION_Y then
+            ev.code = ABS_MT_POSITION_X
+        end
     end
 end
 function Input:adjustTouchScale(ev, by)
@@ -172,17 +177,15 @@ function Input:adjustTouchScale(ev, by)
     end
 end
 function Input:adjustTouchMirrorX(ev, width)
-    if ev.type == EV_ABS then
-        if ev.code == ABS_X or ev.code == ABS_MT_POSITION_X then
-            ev.value = width - ev.value
-        end
+    if ev.type == EV_ABS
+    and (ev.code == ABS_X or ev.code == ABS_MT_POSITION_X) then
+        ev.value = width - ev.value
     end
 end
 function Input:adjustTouchMirrorY(ev, height)
-    if ev.type == EV_ABS then
-        if ev.code == ABS_Y or ev.code == ABS_MT_POSITION_Y then
-            ev.value = height - ev.value
-        end
+    if ev.type == EV_ABS
+    and (ev.code == ABS_Y or ev.code == ABS_MT_POSITION_Y) then
+        ev.value = height - ev.value
     end
 end
 function Input:adjustTouchTranslate(ev, by)
diff --git a/frontend/device/kobo/device.lua b/frontend/device/kobo/device.lua
index 44ef60d1e..924ccb169 100644
--- a/frontend/device/kobo/device.lua
+++ b/frontend/device/kobo/device.lua
@@ -76,7 +76,7 @@ function Kobo:init()
 
     -- it's called KOBO_TOUCH_MIRRORED in defaults.lua, but what it
     -- actually did in its original implementation was to switch X/Y.
-    if self.touch_switch_xy and not KOBO_TOUCH_MIRRORED 
+    if self.touch_switch_xy and not KOBO_TOUCH_MIRRORED
     or not self.touch_switch_xy and KOBO_TOUCH_MIRRORED
     then
         self.input:registerEventAdjustHook(self.input.adjustTouchSwitchXY)
diff --git a/frontend/ui/screensaver.lua b/frontend/ui/screensaver.lua
index b28d79b63..0bbd38f6d 100644
--- a/frontend/ui/screensaver.lua
+++ b/frontend/ui/screensaver.lua
@@ -98,12 +98,13 @@ function Screensaver:show()
     -- first check book cover image
     if KOBO_SCREEN_SAVER_LAST_BOOK then
         local lastfile = G_reader_settings:readSetting("lastfile")
-        local data = DocSettings:open(lastfile)
-        local exclude = data:readSetting("exclude_screensaver")
-        if not exclude then
-            self.suspend_msg = self:getCoverImage(lastfile)
+        if lastfile then
+            local data = DocSettings:open(lastfile)
+            local exclude = data:readSetting("exclude_screensaver")
+            if not exclude then
+                self.suspend_msg = self:getCoverImage(lastfile)
+            end
         end
-
     end
     -- then screensaver directory or file image
     if not self.suspend_msg then